Unprotected sex

The dreaded unprotected sex! Okay, ladies help me. Me and my recent boyfriend have had unprotected sex, I'm the worried type so its not a surprise that this worrys me. I don't really know what to do, I'm too young to be pregnant and I don't know how I should go about this? I mean yes take a test but I don't know where to buy one from, what to say, if you have to be a certain age, all that kind of stuff? Someone calm me down please I beg✨💕