I am 16 week 4 days pregnant. From last 3 - 4 days i am feeling some pain like sometime in leg some time light headache. But since tomorrow i am feeling tail bone pain which is now exaggerated to back pain. And with that sometimes i get period like feeling in my stomach. Not cramps in stomach , just a feeling i used to get 1 day before my period starts. This tail bone pain issue i have before pregnancy but it was very minor. It pained only when i sit for very long hours. This period feeling is really making me panic.