OK so I had sex sometime in February and never skipped a period. My nipples were really tender a week after we did it (and around periosd) then like a few days later they starting leaking milk. They've grown a little bit since then and just today the right one started to ache. My gut hasn't grown an inch so I know I'm not pregnant?

Many women have a period while they are pregnant, and as for not showing some women don't. If I were you I would buy home test just to make sure.