From Verbal Offer to Contract

I've been offered two jobs, the first one they sent the contract to me via email two days later, for the second one it's been a while (over a week and a half, but there was a four day weekend in the middle) and I haven't heard anything except for that verbal offer. Should I be worried at this stage? Or should I leave it a while longer before I contact HR. It's a small HR department and I don't want to harass them.

Advice is appreciated,

Thanks!