Braxton hicks at 15 weeks

E
Im 15 weeks pregnant and have been getting horrible cramps along with lower backache and my stomach feels so tight, it hurts soooo bad. Its my second and the pain is kind of the one i had when i was in early labor, i dont remember EXACTLY but it reminds me of that pain. What could this be? I don't have my appt until the 15 😐