White thing? STD!?!????

I have been sexually active and yes I have gotten check and I'm clean. Im yet to go to another appointment but the clinic is booked. Anywho, i just noticed this white thing under the entrance to my vagina. It wasn't there in my last appointment..and well Im confused. Here's a horrible drawing of it. 
It looks like a tonsil, and I'm scared that I might not be clean anymore. Please help. I'm stressing out. 😰