Stretch and sweep

So I'm 37 weeks and already dilated to 3cm, cervix is only 1cm long and bub is sitting very low.

I'm very shocked as it's my first baby! And I was closed and 0% effaced just 2 days beforehand

I got given a stretch and sweep (was uncomfortable but not painful) I'm just all round shocked at the moment

Should I expect labor to be soon at all?

I've heard some women can be quite far dilated for weeks on end