Hi,
Welcome to the ehealthforum and I am glad to help you out. It is not uncommon to find numbness in the arms or legs during pregnancy especially in the first trimester. This is because of a result of a misalignment in the low back vertebra, sacrum, and pelvis or any combination of those. It can also be due to compression of the nerves. Take as much rest as possible, elevate your leg while sitting and eat a healthy, nutritious diet. Also try standing in such a manner that your weight is born by both the legs equally.
If the symptoms persist, physical therapy may help. It is advisable to consult a gynecologist in that case. It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For an exact diagnosis, you are advised to consult your doctor. I sincerely hope that helps. Take care.