could i be pregnant?

my boyfriend and i have had sex 4 times. but we do multiple sessions. mainly 2-3 sessions each time. he pulls out, but i was told that even though he cums on my thigh area// the sperm can travel to get to uterus from outside. anyways, recently he pulled out, came on my back & put it back in. is there a possibility this could lead to pregnancy? i’ve notices i’m sleeping a lot more then usual (normally an insomniac); my stomach hurts, i feel bloated, and my nipples are highly sensitive. Note - i just got off my birth control 3 weeks ago..

- Someone please help!