I have the error log if anyone needs it and I have some custom content on the lot too:
When in doubt,
always post an error log. Hell, regardless of doubt or not, you should
always post an error log. Well... only if it's an Object error log (the audio logs and crash logs don't seem to be all that helpful, or so I've read).
Object error logs, typically, will allow one to trace through the stack and potentially identify what BHAV and what line of code in that BHAV (as well as what object that BHAV is from) that is causing 'jump bug' type errors.
thanks for the help, I turned off the cheat untill she had the baby then turned it back on, all seems fine now but whenever I have a pregnant sim in any of those 2 lots I should remember to turn off the cheat before saving! I'll post here if anything like this happens again!
This is not really the recommended way to deal with such problems. It only temporarily resolves the issue for now, but you may ultimately be on the path towards a BFBFVS.
Who knows what kind of weird stuff could potentially be happening, especially if it involves new sims being created (perhaps with bad sim data?).
Ste