I’m kinda worried help me out pls

I’m 4 days late and I’m kinda worried, I had sex twice since my last period both times we used protection. I have no pregnancy symptoms and this year my period has been on a weird schedule but I’m not sure what to think, sometimes comes early and sometimes comes late. Before my period used to come every 30 days but these past two months it’s been coming every 21 days. Should I be worried that I might be pregnant or is it just a late period