We are trying to have a baby, my next period was not heavy, first day there was a brown blood

Hi I'm 22yrs old. I have a question my fiance and I we trying. The thing on the 21th of december I was ovulating and we had intercouse. On december my periods where on the 5th. But on jan it was on the 9th and it lasted for 2days it was not heavy to fill in a pads. On first day only brown blood came out it lasted the whole day. But later. Had my periods which lasted for 2days. I'm I pregnant?