no orgasm!

How do you know when you have an orgasm? I know everyone is different, but how can you tell? We been married for two and half years, and I don't think that I have had an orgasm, there is been about ten times when sex feels amazing but at end I feel like something is missing, I don't seem to be done and I always want more. My husband just started to use his fingers and feels really good but again, I feel like something is missing, he always finish and I don't, I talked to him last night because sometimes I feel unsatisfied with sex, I just don't know what to do, there is been many times when I'm about to finish and boom he's done😑 he last longer if I'm on top or from behind (like a spoon) but I hate that position because doesn't give any pleasure... he can be doing I just don't feel anything. He also likes sex if I'm in legs and arms but he only last like two minutes. Any advice?? I just don't want be like this for the rest of my life. TIA