Help pls

So my period came late, it was due july 1st but came on july 13th. Although i did have blood spotting on the 12th.

But anyway i had unprotected sex on 17th july but i was 5 days into my period. My flow was light at this time there wasn’t blood on my pad but a day or so after my flow returned.

On Monday 29th (3 days ago) me and my boyfriend had unprotected sex multiple times at his house but it was like every time we done it we’d lay down for like a hour then do it again, it just happened.

But yesterday i felt really bloated, and today i feel bloated too and when i was sleeping i felt pain in my side abdomen 😭. And my lower back was hurting. And my nipples look more out and weird looking and my boobs are quite sore.

Im having this sort of cm:

My period is due August 10th but im abit worried.

I know what me and my boyfriend did was extremely irresponsible and I’ve tried birth control but my mum doesn’t approve. I’ve taken 2 plan b’s before. One in may and one in june so i dont wanna take more.

*me and my boyfriend are only 15 so this is really scary for me, i feel like he doesn’t understand about pre cum because whenever i tell him im scared to have unprotected sex he tells me to just trust him*