Idk what’s going on... HELP?!?!

So the past 2 months I went from regular periods to irregular. My periods have been shorter and coming twice a month I’ve been having my what I think and hopefully is my period twice a month now. And recently before intercourse I had what I thought was spotting but it went away but after intercourse with my boyfriend I went home and woke up to blood in my pants. Like a regular flow of period blood along with cramps, and the regular period symptoms. I’ve had my period this month already, and now have it again? I’ve been stressed and working a lot lately and school tipping that. Don’t know if that’s a factor. Or what’s going on. I had taken a Plan b a couple weeks ago could that be a factor? Rough sex? I’ve had sex before this is not a first but this is the first time I’ve ever spotted or had this happen before a “period” or whatever is going on. But I’m also not on birth control. How do I talk to my parents about going on that also? But any idea if I should be concerned about pregnancy? Or if having regular periods then having irregular is normal does this sound normal? Thank you!!