Have a feeling I’m being used!

How do I know if someone I am dating is just using me? I met this girl online a few months ago, and she always has a good time when we are together, provided we are doing something like dinner, or a movie, or something that involves me paying for us both. When we aren’t on dates, she is not very communicative, and I get the feeling that she is happy to meet only when she gets something out of it. She doesn’t talk about herself much, or tell me much about her personal life, and we have now been on five or six dates without me getting a sense of where this is headed. Should I assume she isn’t interested and stop meeting her?
If you feel used and can’t get answers to questions in your mind, you should be more direct and tell her what’s bothering you. At this stage, you have nothing to lose because this isn’t a relationship, and she is under no obligation to get into one with you. If she isn’t communicative, ask her why she won’t answer specific questions. If the financial situation upsets you, ask about splitting all bills. If she refuses and turns you down, you will have your answer. Either way, the longer you presume things, the higher the chances of you becoming resentful towards this person, which isn’t fair. So, call her and tell her exactly what’s on your mind.

I met this guy two months ago, and like him a lot, but he always asks me out on weekends, and I just want to take it slow because I’m not as social as he is. What if he assumes I am not interested? How do I balance his expectations against my own personality?
Why will he assume you are not interested without you specifically saying something to that effect? If you aren’t social, and need space, nothing stops you from asking for it. Without you being vocal, how will he get to know what you’re like?