Increased libido!

So throughout my pregnancy, and before, I've never had a high libido, in fact I'm quite happy to go for a few weeks without sex (don't judge me, it's been since a few things have happened to me in my past) my husband is cool with it and understands the reason but we always had a healthy sex life. Anyway so since pregnancy I just can't face it, it's been uncomfortable and not enjoyable as I've gotten further along. I'm now 38+3 and last night at 3.30am I woke up, gagging for it! I mean seriously NEEDING to have sex, luckily hubby woke up to get a drink and was more than happy to do the deed but I then stayed awake for 2 hours because I just wanted to keep going! Does anyone know why this is?