Hey SerenityLee,

I had to have one early because i had a bleed. Anytime you have a bleed you should get one done (well if you're a neg blood type.. not sure about other blood types). I would try and explain why, but i've never really grasped the whole concept! (i think it is something about your blood and the babies blood mixing.. your body realises that there is a different type of blood and creates antibodies to get rid of them, ie. get rid of the pregnancy - don't take my word for it though, thats just my understanding of the whole thing)

I had one after my m/c in jan this year too (cause obviously there was a bleed.. a very large one )

I also had a bleed at 16 weeks with my DD, and had it then aswell.
Other than that, i still continued to have the ones at 28 weeks and 33 weeks.

i hope this makes sense! LOL! like i said i've never really understood the whole thing!