Wa'alaikumassalam sis! Eh, bleeding during bowel movements tu memang boleh happen during pregnancy, hormones and constipation often go together, tapi sebab you're at 20 weeks, better safe than sorry lah. Please call your doctor or go to the clinic today okay, just to check everything is okay with baby and make sure it's nothing serious. A few of us mums go through this, tapi better to get it checked out properly so you can relax, ya? Don't worry too much, most cases fine je, but doctor needs to see you.