Sorry to say, but I had the same thing happen, and it led to a NASTY problem. I ended up having to have the crown removed and because of the gap that had been there, the small portion of tooth that the crown was glued to had rotted out which then lead to the new dentist having to remove it. He litterally had to dig most of it out and then dig into the gum & jaw to get it all out. Now, I have to either deal with a missing tooth or get an implant.
I had been asking my now former dentist (the one who did the crown) about the gap from day one, and he kept saying, "Oh, it's fine. There's no problem."
Well, when I started having pain in that area, I asked about it again and he continued to say no problems, the crown was correct and good. He lied. I was eating spaghetti one day and felt some kind of cracking under the crown. I went to a new dentist the following day and he told me the crown had to come out, yadda yadda yadda. He never bad mouthed the former dentist, but he did say the crown was not put in properly and that there should never be a gap.
I truly hope you don't end up with problems. It's not fun at all