So sorry to hear you're in pain, Broody. Go and have a look on the Pevic Partnership website - that will talk you through the symptoms.
www.pelvicpartnership.org.uk/symptoms-of-pgp.html
Do you have any pain in your inner thighs or down your legs?
I am not sure if it sounds like PGP or not - mine was around the back so I don't have personal experience of pain in the area you describe. However, I would suggest that the best thing you can do is to go to your GP on Monday and be prepared to demand ask for an urgent physio appointment if they think it could be PGP. I think that the sooner you can get a diagnosis, the better chance you have of managing it.
In the meantime, do regular pelvic floor exercises and be careful how you move around, which it sounds as if you are.
Mine hurt when I moved into positions that put a strain on the area of the pelvis where I had stiffness. For example, getting out of the bath, leaning forwards to pick something up, getting in and out of bed.
Hope you get a good night's rest and feel better tomorrow.