Sometimes that happens to me too, I get crazy embarrassed.
I think it's just a change of your female balances up there, cos usually we just won't have sex for a few days and it all goes back to normal.
Just keep an eye on it, don't put anything up there. If it doesn't improve and there's no smell and it starts to itch, probably a yeast infection.
If you can, just have a doc check ya out if it really flags a concern for you.
Could be yeast or bacterial. Bacterial vaginosis there is usually a foul fishy smell after sex. It requires an antibiotic. An yeast infection usually causes itching plus discharge. If yeast you can get over the counter cream at any store.