intermittant bleeding and severity...pregnant?

I had been on the pill for a year and the last month to month and a half my partner and i have been trying to get pregnant. I had a short and light period two days after stopping the pills and we had sex throughout the period and the entire month. A few days before i was supposed to have my next period i had two days of really light bleeding...enough to need a tampon...but it only lasted 2 days, that is not normal. And we continued trying. then no bleeding for a week and i woke up lastnight bleeding and have had mild cramps today. I have been really tired, moody, nauseous, having cravings, urinating more often, and my breasts have been a little more sensitive than normal (but i kind of bundled that in with the bleeding thing)for the past week or so...i took a pregnancy test today (while still bleeding...prolly not the smartest thing to do i must admit, and my period wasnt due till wednesday) and it was negative. how long should i wait to re-test and should i even be concerned at this point?