Sudden sharp pains at 28 weeks??

I’ve had random cramps this morning only once or twice and mild but then one was awful, so painful I couldn’t move then it faded quite quickly. I was only lay on the sofa so it’s not like I moved and did anything to cause it. It’s in the same place slightly right but low in my abdomen. I know round ligament pain can vary but this just seemed odd and different to how they have felt? I’ve not had any more since and I’m going the hospital for my 28 week bloods in an hour so I didn’t know wether to mention it or if it just sounds like a bad ligament pain type thing? I didn’t have it with my son but have had more cramps this time round. Always something to worry about 🙄