I have a bump on the roof of my mouth. looks like its got a white head on it but it also looks red/purple. ive been taking keflex and its like going up and down in size. its on my hard palate. im a 27 year old female ideas on what it could be?

It is not feasible to provide a meaningful opinion without additional history, physical examination and may be some tests. It would be prudent to talk to the doctor who prescribed you Keflex. Wish you good health!

Could be insect bite, bacterial infection of tooth, sinus, or gums, burn, virus infection, traumatic injury, neoplasm, parasitic infection, or scores of intra-oral lesions. Of all these, antibiotics are effective at treating only bacterial infection. Keflex would not be my first choice. Please stop self medicating. See your Dentist or a specialist Oral Pathologist. You need hands-on treatment.