3 Q's: cramping & childcare

[~Kim~]

Cramping is totally normal. Even though that little creature is tiny it's already making everything stretch.
Ultrasound - when did the sonographer/doctor tell you you needed another one? Generally 6-7 weeks for a heartbeat, but there is some evidence to suggest that unnecessary u/s can do more damage than good so that's something to weigh up too.
Exercise is great for you while you are pregnant, and will help you to have a healthier pregnancy than one without exercise, however if it's hurting, like any exercise any time you should stop. During all of my pregnancies I was a policeman, dealing with all sorts of lovely (not) people and doing all sorts of things for quite a while further into my pregs.
As for snotty kids and pregnancy well, there's lots of mamas who've brought healthy babies into the world while they ran around full time after sick toddlers.

Try to relax hun.

[Floweryfields]

I wouldn't be too concerned about the snot, but be sure to wear gloves and wash hands well when changing nappies, wiping bottoms, etc.