lump on cervix

[miabonzia.livejournal.com]

The other day my boyfriend was fingering me and he said he felt a strange lump on my cervix (we established what that was a while ago when he asked about the thing at the top of my vagina lol)  I checked it out myself and sure enough, there is a lump there.  I'm 17, been sexually active since I was almost 15, and have never felt it before.  I was on the pill for a while but for the last 18 months or so I've been on the depo provera.  I just got my latest shot this week.  Is it normal for the cervix to have a lump? Or should I see a doctor? 
If so, what should I expect? I've never been to a GN or even just a GP for a check up "down there", mostly because I've never needed to.
Oh, and when I was 2 I had an STI - genital warts.  No one is quite sure where it came from or anything, and it was all cleared up by the time I was 3 and I've never had any problems.. but could it be making a come back? Could this be it?
Please help!