there's no possible way at all....RIGHT?

I had sex the day before my Dr decided to do a c-section early.  I have been so so so sick for the past 4 weeks, I can't eat, I can't stand the smell of just about everything!....there is no way I'm pregnant again, correct.  I should know this answer without a doubt, but I honestly don't.  I also figured taking a hpt would be pointless as it would show a false positive since it's been less than 4 weeks since delivery.