IUD falling out

So, I just got a copper IUD 2 days ago. My bf and I had sex later on the same day that I got it. Today, I started noticing something poking my vagina at work and it was a sharp pain. I left it there for some hours, then I got home and felt that my iud had almost entirely fallen out. I then pulled out the IUD.

So I have questions:

1) has this happened to anyone else?

2) is there a chance of pregnancy?

3) do you think my gynecologist will replace it without having to pay double?

4) did it get dislodged or was it never in place?