D.M.
If it has been two weeks, please take your little one to the doctor...my rule of thumb with anything is if it's not gone in fours days, go to the doctor (as advised by NICU nurses and son's Pedi).
My son used to get sick like this ALL the time and while it may be nothing, it could be something if it's not gone yet. In my opinion, finding our your little one is okay is worth that co-pay.
It also, sounds like you're doing everything to make her comfy so, it would be best to get a doc's thoughts on how to get rid of it.
Good Luck.