I Had Unprotected Sex With My Gf ( Age 41)

i had unprotected sex with my gf ( age 41) on 23rd dec., within the next 8 hours she had am I-pill., and after a week she got her period ( jan 1) but it was a large dark brown splotchy discharge., her second period was on 28th jab ., but yet again it was in large dark brown splotchy discharge., should we be worried about pregnancy