Hiya hun! Nice to see my fellow testing-day buddy over here
I had exactly the same last week, the day before my BFP so two days or so before AF was due. Mine were so bad that I was literally doubled over at my desk at work for an hour or so! I've never actually felt them that bad before. Then they just disappeared. Thankfully I didn't know I was preg at the time otherwise I know I would have been worried too... But that was 6 days ago and my test sticks are getting darker each day so I'm sure it was just a bit of baby getting all nice and snuggled into its new home. And it sounds like yours is too!
Is this your first? Its mine so I have no idea what to expect and what's normal. Its so lovely but also so worrying being this early on isn't it. Next time I'm not testing until I'm sure I'm 12 weeks gone haha! Xx