Boyfriend came in me New Year’s Eve and day

Bf came in me New Year’s <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> and day. It was two days after my period <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> says my fertility window opened on the 2nd. Should I be worried?