to re-test or not...

Me and my guy had a bunch of sex this month. Around ovulation he claims he pulled out in time so we didn't get back up contraceptive or anything. Another time this month he finished in me and I took plan b on the second day. I took 2 tests before my period was supposed to come and both were negative. I felt some slight cramping yesterday and thought, "ok, here comes my period" and nothing but a little tinge of blood when I wiped. Nothing period-wise is happening down there. I feel so bloated that if you stick a pin in me I'd pop. Should I re-test in another week if I still don't get my period?