So, that discomfort may be hard to shake at first, especially if you've previously dealt with it by asking your partner to check in or do other things where the bulk of reassuring you falls to her. Learning to self-soothe takes time and practice.
But if you're feeling that way constantly, that's a sign that something deeper is going on. It may be helpful to start out by asking yourself where those feelings are coming from. For instance, do you have trouble with trust in general? Are you carrying around some beliefs about cheating, or your own worth as a partner, that might be feeding that insecurity? Is there something about a place she goes or a person she interacts with that gives you an "off" feeling? Something else entirely?
Even if a partner was totally okay with that level of monitoring, it's not a good habit to fall into in your relationships. As mentioned already, part of being in a relationship is learning how to trust the other person and manage any insecurities we have around that. If the underlying trust issues aren't addressed and are instead papered over by something like constant checking in when one partner is out and about, odds are they'll start turning up in other ways. I really like the way Heather explains it in this article:
http://www.scarleteen.com/article/advic ... shes_doing