Swimming tomorrow? Self-concious!?

Okay, so I am 1 and 5'5" ish and weigh like 134. I have a semi flat stomach but under my belly it goes out a little. Im really self-concious because im going to be in the ocean alll summer and since im going into 9th grade boys will be there, and all the other girls have flat stomachs. should i be conscious? and any tips how to get rid of this? I have type one diabetes and i eat this usually: Breakfast 2 egg whites with swiss. Lunch: Salad, or sushi, or a small sandwich. Snack: an apple or Small bag of chips. Dinner: chicken caesar salad, or fish, or tofu pasta. I cut our my red meats which helped me lose weight, and i love fruit! I also have softball 2 hours 5 days a week, and i do pilates for like 10 minutes before bed.