Im 20 yrs old and i was wondering was it possible to get your last period within the first month of pregnancy?

My last NORMAL period was May 2nd and got my period again May 30th what seem to be shorter and maybe a little lighter, now im due again for AF tomorrow but i dont have any symptoms of it coming, i normally have gas, and very tender breast and i have no signs of neither so i was wondering could i be pregnant with having my last period and no more until after the baby comes?......if anyone could help with your experience or advice i would greatly apprecitae it :-)