Question for women that have already had babies

I am 22 weeks tomorrow and on Saturday I went to the hospital because I was having lots of cramping. They hooked me up to a monitor and I was having little contractions (very small on the monitor and only lasting about 10 seconds) they gave me a shot to stop the contractions and it worked. But last night when I was in bed I felt like I was having worse ones (not horribly painful but enough to kind of bug me) they went on for about an hour and a half. Now tonight laying in bed I'm having them again..... The nurse at the hospital told me that this was pretty normal and that some women have them throughout their entire pregnancy. I have an appointment with my OB on Thursday. Does this seem normal or should I try to get in earlier? I'm just worried that it could hurt my baby girl. Could it maybe be Braxton hicks?