Tailbone pain from sex?

[Glorious]

Is this normal, or should I be seeing my GP / a gynecologist about this?

I'm pretty new to having sex (by which I mean this past summer). I've found that when my spouse and I have penis-in-vagina sex I have pretty severe pain in my tailbone. It's a sharp, radiating sort of pain and only seems to occur when things go in too deep. The only other time I experienced it was when I had my IUD put in a couple of years ago (it came from the nurse measuring the depth of my vagina rather than the insertion of the IUD itself. Inserting the IUD was actually less painful). I haven't had a pap smear before, that's not recommended in my province until someone is sexually active (or if they have been in the past). It doesn't really interfere with our sex life, I just remind my spouse when needed and he adjusts accordingly. But if it isn't normal, I wonder if I should see a doctor about it? Especially if I want to have children some day? I took a look at the article you folks wrote on pelvic pain but wasn't sure if tailbone pain is the same thing or something different?