My DH and I were recently on exchange with missionaries (we are ward missionaries) and they'd been working with a couple for several months on getting toward baptism. One in the partnership wanted it and the other didn't. They were sort of at a standstill the night we were there. I asked the elders about it as we were taking them home and they said that they couldn't continue to visit the couple if they weren't going to progress towards baptism. They were REALLY upset about it, as they like the couple as people, not just investigators. I asked them about it. They indicated a two-fold reason: 1) they are on a spiritual mission right now. If they aren't teaching the couple, as the couple doesn't have further questions at this time, they are simply sitting there making small talk and being friends. While it's good to have a friendship, their mission is for spiritual reasons and developing a (in this case - maybe not yours) goofy friendly relationship where they aren't doing missionary work will remove the Spirit in some ways from their work. They work hard to stay focused on the Spirit and their work in the field.
2) They don't want to pressure you. You've said "not right now," so they are giving you the space that you need/want at this time. In their position, they can only do so much until you are ready for baptism. They should still visit here and there but I agree with a previous post...ward missionaries should/could be picking up here and really making you feel welcome, even if you aren't baptized yet. I
t's a perfect church...but not perfect people. These missionaries are only 19-21ish...they don't have perfect social skills!