aitchyd, you can get morning sickness from any stage in early pregnancy - with my two it didn't kick in till about the 7th week, but I know people who've had it practically from conception. You're doing the right thing in eating a little and often, and you should only eat what you fancy. Don't force yourself to eat something just because it's good for you if you can't face it.
The abdominal pains are normal - weird, and scary, but normal. They can feel, like I said before, like period pain, but it's only if the pain is bad enough for painkillers, and accompanied by bleeding that you need to worry. And even bleeding is not necessarily anything to worry about it provided it's dullish brown in colour, and more like spotting than a proper period.
But if you have bleeding of any sort, go to your local hospital's early pregnancy unit for a scan to be checked out. It's always better to have your mind put at rest, or your worst fears confirmed, than to worry yourself to bits in ignorance.
and bonkerz, I had the dull ache in the groin as well - I think it's the uterus gradually working its way upwards to where it needs to be for the duration of the pregnancy. In any case, no one prepares for the absolute weirdness of early pregnancy, and the worst thing is not knowing what's normal and what isn't!
Good luck to all of you - I hope you all have lovely, healthy pregnancies, followed by lovely, healthy babies.