One-Sided Leg Numbness??

Hey girls, has anyone else experienced one sided leg numbness/pain when sitting?? Everytime I sit my left leg goes numb! This has been going on since I was about 18 weeks and I'm now 21+2. I know sciatica is normal in pregnancy but it just feels way too early for him to be pressing on my nerves! Sometimes it's so uncomfortable I have to lean on my right side while sitting 😰