Life Problems...Depressed?

So this might be pretty long sorry lol but I just need to vent because I have nobody else to vent too. So last week my mother went to urgent care and then sent to the hospital due to something that was serious she had emergency surgery & everything went well she still is in the hospital in a lot of pain. I have been extremely stressed over that & now she has to go to rehab for therapy & has to stay there for 3 weeks. So now I am more stressed about that. Then I keep thinking about me having sex I believe 4 weeks ago and I started my BC pills 4 weeks ago and I did have protected sex & now I am stressed because all I think about is me being pregnant. I heard when you take the white sugar pills that's when your period is suppose to start & I just took my 3rd white pill today. It really feels like my period is about to start though but idk. & around 8 everynight my back starts to hurt and my breast hurt just alittle but I don't feel sick or anything like that. I am just overwhelmed and stressed to the point where I think I am depressed. My birthday is next weekend and I don't even feel excited about it. I am just stressed about my mother & I know school is about to start back up soon & me working too it's hard. I think I am being parnorid that I might be pregnant but everything was protected so idk. Should I just stop worrying? I just wanna cry at this point it's too much going on in my life rn