If a girl gets their period 1 day after , is it still possible that she is pregnant?

Yes, because the fertilized ovum may not have made it to the uterus in order to be shed during her period and can still implant. And yes you CAN have a minstrula cycle when you are pregnant. I had NORMAL cycles into my 10th week of pregnancy, my cousin was 6 months pregnant with NORMAL cycles. No two pregnancies are alike, no two women are alike.