Prescribed doxycycline 100 mg for epididymitis and took it for 4 days and recently stopped it as I started getting headaches and still not going away, when will this headaches go away and will they as I have stopped taking the antibiotic..

Doxycycline headache. If your testicular pain wasn't improving after 4 days of doxycycline, it's a good bet you don't have epididymitis after all. More important, a rare doxycycline side effect is increased pressure in the brain (pseudotumor cerebri), which can cause severe headache and sometimes is quite dangerous. Stay off the doxy and contact your doctor ASAP. Get care immediately if any vomiting, confusion, etc.