can take a pregnancy test? According to the two pharmacologists I asked, the anti-biotic should have been out of my system, but my gyno still warned against it. I don't THINK I'm pregnant- my period SHOULD start on Sunday or perhaps Monday, but I'm not PMSing, my stomach's hurting more than normal, and I just feel kind of weird. I took a pregnancy test this morning and it was negative- but is that too soon to take one? When's the earliest I can know? Thanks