premature labor

I went into L&D; over pain in my stomach and was told I might be doing into premature labor. when i arrived I was having really bad contractions, i was having 5 in an hour. they gave me IV's, steroids and had me in bed rest for a whole day overnight I was dischgarged once my contractions separated. I'm 34 weeks 2cm open, they told me I had to be on full bed rest. this is baby number 3 and I've never been through this and i don't quit understand why they won't just give me medication to stop my contractions instead of preparing myself and baby incase he comes? And yess I asked my doctors these things she told me at this point they wouldn't stop me from going into labor but she also told me it isn't ideal for him to come until 37 week. I'm confused and scared. please any moms that have been through this and can tell me a little about their story.