I used to have a clear discharge now it's white and thick. there's also soreness. during sex there's some dryness. neg. for stds and infections.

Yeast?: This is suspicious for vaginal candidasis (yeast infection). It can be difficult to diagnose. Return to your doctor; it should be possible to sort this out. Or try one of the over-the-counter vaginal yeast treatments. Look for a product with active ingredient ending in "azole": miconazole, clotrimazole, teraconazole, etc. If that doesn't work, for sure return to the doc. Good luck!