non visible bump at 17 weeks

Normal for FTM’s pump to be small as everything is not stretched yet. You should be able to identify (from stomach juice) the movements from around week 22~25 onwards. From there it will be more obvious. My bump only really showed at 8months pregnant 😃. Headaches are normal, however for the sharp pain, I cannot advice.

Normal for bump to be small. As for movements, you can check with your gynae if the position of your placenta is anterior or posterior. If its anterior, chances are you would feel the movement later. I have posterior placenta and felt my baby movement from week 15-16.