Am I pregnant? what should I do? *teenager*

Okay, first I’m going to warn you this is going to be sort of a long story.

Backstory: I’m 16 and a senior{very young senior, I recently lost my virginity a month or so ago (totally consensual and felt completely ready) since then I’ve discovered I have a REALLY high sex drive. So me and my boyfriend have sex almost everyday multiple times and Condoms are expensive. Anyways we had unprotected sex a week ago on Tuesday and (our birth control has always been withdrawal I need to go to planned parenthood but my mom is a really strict catholic mom and I can’t talk to her about anything and I don’t drive so it’s very difficult for me to get on birth control anytime soon) so he came in me this time for the first time it was my fault but I dont wanna expose myself. I found out from this app It was my most fertile time and I was at high risk for pregnancy so I walked two miles to and from a rite aid to get option 2. Since then i have been eating four times as much as I usually do I have insane back pains and stomach pains especially on the left side of my stomach and I’m super super irritable and angry all the time out of nowhere. Im supposed to start my period in six days and I can’t tell if it’s me PMSing, something really bad is happening up in there, or I’m pregnant.

Has anyone else had any similar experiences or any advice?