Actually yaar, mild pain can happen because the uterus is stretching, but don't ignore it. If it's a sharp, constant pain or if there's any spotting, call your doc immediately. Safe side rehna hamesha better hai.
I had round ligament pain in my second trimester which felt like a sharp pull in my lower belly when I got up too fast. My doctor said it was normal, but they checked me just to be sure. Please mention it to your gynac to rule out any infection.
Beta, early pregnancy me thoda khinchav toh hota hi hai because baby is growing. Rest as much as possible and don't lift heavy things. But agar dard bahut zyada hai, toh bina bimar hue doctor ke paas jao.
For mild stretching pain, lying down on your side with a pillow between your knees helps a lot. However, if the lower abdomen pain is sharp or accompanied by cramping or bleeding, please consult your doctor immediately.