Post-coital bleeding can occur for a number of reasons, and is nothing to take lightly. Here's a look at the top 10 causes of vaginal bleeding after sex: Cervical Dysplasia,Chlamydia, Gonorrhea, Vaginitis, Cervical Polyps,Trichomoniasis,Vaginal Yeast Infection, Endometrisi, Uterine Polyps, Fibroid tumors.

Since you have had some STD testing done when you went to the ER and it came back Neg-, I would suggest being retested with a GYN as well. I would also get a full blood work up, which should include checking your hormone levels as well.

The lump you speak of is probably a boil/infected follicle, which is common in these areas. Apply a moist warm compress to the area several times a day, which will help bring it to a head to burst. You can also take ibuprofen as well, which will help with the pain, the warm moist compress will bring comfort too. Don't try to squeeze it, letting it burst on it's own is the best way. If you have more than one you should bring it to your doctors attention, you may need a course of antibiotics.

So do make an appt with a GYN at this point so you can get further evaluation on the irregular bleeding.

Hope this helps, If you need anything else please feel free to ask. If you found this helpful don’t forget to click the *accept* button!