I've had two children who have done that. My first was just a very frequent waker, frequent nurser and didn't sleep through the night until she was 4 years old. She was still waking every 1-3 hours even when she was 2 years old-drove me batty, but she finally got down to (usually) just one waking a night by the time she was 2.5 - 3 years.
My second was (is still, actually) a very good sleeper, slept 7 hours in a row several times at only 2 months of age, but by the time she was 6 months or so was waking every two hours. I figured it was a phase. Fortunately it didn't last too long, at least not that I recall.
You can always try a crib if you think it will help; it could. Try not to get your hopes up, however, because it can just lead to resentment and this feeling that your child is unusual in this regard, or should be more like your first. Not that I am good at taking my own suggestion, but so many times I'm convinced that my child is just not normal, and that other people's kids do X or Y and why don't mine do that (even still to this day, LOL). Upon talking to people in depth, however, I find out my perception really isn't accurate.
The person whose child is sleeping through the night at a young age seems more likely to talk about it--either because she is so surprised and pleased about it, or because she thinks it's because she is parenting the right way and wants to teach you how to do the same. Sorry if that sounds critical, it's just what I've experienced. I also don't mean to sound preachy but I know part of my own difficulties in dealing with sleeping habits was my feeling that it shouldn't be like that. Good luck and good sleeping vibes to you!