My period is late what should I do?

I'm 17 and I'm sexually active. I don't use protection but my boyfriend never finishes inside of me. The first day of my last period was may 23rd. On june 16th I started to receive stomach pains so I went to the doctors. (I've had a history of stomach pains, like ovarian cysts) The doctor asked if i was sexually active, i said yes. He asked if i was on the pill, I said no. They gave me 3 tests. He said he would test for pregnancy. A urine test and a blood test on the first day. He said it was negative but he still wanted to see what was wrong with my stomach. The second I took an ultrasound and they stuck a camera up my vagina but did not mention anything about pregnancy. I have not done it since i've been to the hospital. I took pills to relieve my stomach pains. apo-naproxen and apo-cyclobenzaprine. Now It's june 25th and I still haven't received my period. I stopped taking the pills a couple days ago because I was worried if it was messing up my period. All i started to feel was my breasts are growing and sore but it isn't unbearable pain, gassy, and occasional stomach pains. Should I be worried?