I know this is gonna sound mad stupid BUT

I am starting to get worried because I am 2 days late on starting my period (maybe <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> didn't track my period correctly??) Although last time I had sex was in December.. Can I still be pregnant despite me having my period for the month of December/January.