I used to cross my legs all the time and now I can't do it without getting pins and needles. I also can't sleep on my side because I get numbness and pins and needles.
What you are describing is not MS. The symptoms experienced by those with MS are not positional. When a symptom or symptoms are all over it's usually not indicative of MS, MS just doesn't work like that.
I agree you should consult with your OBGYN. Post-partum your hormones can cause symptoms of depression, anxiety and more. Take care and congratulations on the birth of your child!
Diagnosed with Multiple Sclerosis in 1985
PTSD diagnosed Feb 2004 (PTSD since age 2), Anxiety/Panic attacks secondary to PTSD.