Advice,? Does anyone else consider this prego?

Had intercourse Nov 5, I keep waiting for my period to come for this month , I have a lot of white discharge ,lower cramping n back cramping but still no period !! I took a test over counter but still says negative.. I have three other kids that I try using an over the counter and they still said negative too wen I was 12 weeks along ..I've never been this late unless I found out I was prego..