Should I bulk up to get abs or cut more?

No matter what you try to do, you will gain some fat while bulking (and because you are gaining some fat you will also lose the definition of your abs). If I were in your position, I would lean gain up to 15%-18% body fat before you cut down. There is no reason to cut down to 8% if you don't have a solid amount of muscle to show off. To lean gain, you should up your calories above your maintenance level by about 300 calories. Use this http://www.acaloriecounter.com/diet/calorie-maintenance-calculator-daily-calorie-requirements/ to figure out your maintenance calorie level and then add about 300 calories to that (if you aren't worried about gaining more fat then you can add more calories than that). Your protein intake should be about 1 g/lb of bodyweight, fat intake should be about 25% of your total calories, and then the rest of your calories should come from carbs.

At 12% body fat, you probably just need to really work on your ab muscles. Try to do leg raises, high knees, any lower ab focused workouts 3 times a week to build your ab muscle. You can probably also lower your body fat to 10% to make abs more visible. Because your body may just like to keep fat at your lower abs. So suggestions is to do a slight cut (slight deficit) along with a lot of lower ab workouts. Good luck!

8% might be a tad too low. Going low might hamper strength and muscle gains coz your hormones will go out of whack. I would first like to redirect you to google anthony mychal solid base. Secondly, you decide for yourself. If you feel you look too small go on a slow bulk. If you really wanna see your lower abs then cut. When you bulk you must accept a little fat gain. Sorry to say that

I don't do any ab exercises and I have a 6-8 pack.  I do compound core exercises: Squats, deads, shoulder presses, etc.  These will build abs.  Now, being able to SEE your abs, you need to cut fat, period. If you already lift heavy and hard, this should be no problem. I eat constantly, and have no problem keeping my body fat low. It's all about good food choices.  Add some HIIT cardio for 20 minutes when you wake up to accelerate your metoblism.  Reduce carbs and make sure you eat enough fatty acids.  I recommend Vitamin-C and Green Tea extract supplements to speed up fat burning, as well as Omega-3.  Nutrition suggestions: Eggs, protein shakes, low fat greek yogurt PLAIN, almonds, avacado, lean meats, kale/spinach, cottage cheese, peanut butter, peas, fish ... You should be able to eat as much of any/all of that stuff as you need to. If you still can't lose fat, start reducing food intake.

Bulking up wont help you. Bulking up is required when you are looking for some serious muscle mass. So you know which way you have to go. Its a well known fact that if you want those packs to get visible you gotta get you body fat less than 10%. So sweat up and go for cutting programs ( this will definitely affect your muscle mass in proportion). Good Luck with your packs !! P.S. I am almost in the same situation as yours (with that extra deep groove :p ), and lower abs are still a dream for me :P But my body fat % is close to 18.

If you want to get really defined abs you should cut more. If you start bulking up now you risk putting on too much body fat. You would be better off, cutting until your abs are solidly defined and then starting to bulk.

You might never get the definition you are looking for because sometimes it comes down to your basic shape.  Check out arnie https://unidigest.com/en/my/blog/the-terminators-back-with-6-steps-to-success/ he has a 4 pack only. it got more pronounced and on occasion u could make out the shape of the bottom abs, but never was his strongest area. 

Fat is the greatest culprit for abs . When you reduce your body fat it will more visible . My suggestion is eat more protein and do high intensity workout . Cut off carbs intake.

A big misconception people have is their BF % is usually a lot higher than what they estimate.  Have you ever heard; "Abs are built in the kitchen not the gym?"  This is 100% true from my experience.  Yes you need to build your abdominal muscles to make them look well when you are cut, however most abdominal appearance is due to genetics and body fat around the abdominal muscles.To give an example of what 8-9% body fat really is, here is a picture of when I was that lean and it is pretty hard to maintain for a long period of time without your diet being in check.