Please help! Horrible cramps and weird doscharge

It's been five days since my (perfectly normal) last period and I've been having sex with my boyfriend. 
What's weird is that after we're done I noticed LOADS, like a really ridiculously huge amount of weird discharge. It's white-ish and kind of dry/clumpy. I've had yeast infections before and it doesn't look quite like it, mainly because it only appears after I have sex (I don't notice anything weird on my underwear) and there's really a lot. I've been having horrible cramps too, like when I'm on my period, except obviously I'm not. Should I be worried? :/