Rachel i wouldn't worry, i still get the same pains now at 20 weeks. As the other ladies say they are ligimate pains, i got quiet a few when i started excersing again, then again recently after i'd been ill and been laid up. I just remembered - i was out shopping at around 15 weeks, and i had a terrible sharp pain in that area. i was so freaked out and worried i text DH. He looked it up straight away and said first thing that came up on search for 15 weeks and sharp pain was ligimate pain and it was very common for that time. xxx
As for discharge, it comes and goes, think mine went a simular time - but came back couple of weeks ago.
Try not to worry, i know it's hard, i still worry now with every ache!! But it's a big growing time for you, so prob just the ligimates stretching xxxxxxx