Normal or do I need to get checked out?

Currently 19wks pregnant and I have a really strange pain in my left leg which started yesterday afternoon and is not a pain I’ve had before - it’s a constant pain behind my knee at the back and is spreading up my thigh and down my calf (but seems to start at my knee), it’s a persistent pain that isnt relieved by sitting / elevating it, and I also keep having dizzy spells where I go really dizzy for 5-10 mins 😩 I have family who have had blood clots so my mums is panicking that it could be that but it doesn’t feel warm 🤷‍♀️ should I get checked out or just see if it passes?