help, please respond

so i had sex with my bf ab 16 days ago, it was unprotected but he pulled out. i’m on the combo pill and sometimes i take it a couple hours later or earlier than i should. i took my last active pill friday and now i’m on my placebo week. i’ve been crampy and gassy and sometimes i get a little nauseous. i don’t know if i’m just psyching myself out or if i really am, i am so scared, can i be? or could those just be symptoms of my period coming since it is my placebo week?