She didn't have an orgasm!

So me ( a girl) and my girlfriend are 17. The other day I fingered her for the first time, we are both virgins and this was the first sexual thing we'd ever done. So she told me it felt really good , but she didn't cum! What did I do wrong? I asked a friend and she said she never came the first few times she got fingered, but now she does. I'm super scared that my girlfriend feels disappointed. I asked her about it and she said she enjoyed it, I'm scared she's just lying to me make me feel better. What can I do better next time? Is it normal to not cum the first time? Am I being over dramatic about this? ☹️