My boyfriend thinks I'm pregnant

We had sex the day after my period ended, which was about a week and a half ago. I know my body pretty well and right now I should have white discharge showing up in my underwear because of ovulation or whatever. But I don't, which I'm not too worried about. But he is, he keeps saying everything I say (cravings, nausea, dizziness, sleeping a lot, increased arousal) makes it sound like I'm pregnant. So he had me really worried and paranoid that he may be right. But now I have brown discharge much like what happens before my period, but I'm not expecting my period for another 2 weeks at least, so I'm worried something else may be wrong. I'm just so confused and I don't know what my body is doing. Any thoughts?