unprotected sex with pregnancy symptoms and only 17

ok so me and my boyfriend had unprotected sex on june 16th and i guess he came in me a little im not too sure. he must have because he was real scared. but anyways i had my last period june 5th so would that mean i was around my ovulating time and could have gotten pregnant? but i've been having back pain, headaches, horrible nausea, and i cant eat pickles they make me sick to my stomach and ice cream tastes nasty to me! but please get back to me could i be pregnant i started having these signs around the 19th weird. but ok