Gave a birth 45d ago. on breastfeeding.made ultrasound for check,they found small blood clot. said it'll come out by itself. will it or i'll take pill?

Probably : Bleeding inside the uterus is normal after birth. If it's a blood clot it will come out with your period. Also Breast feeding helps you cramp and push blood out as well as squeeze your uterus so you bleed less.

Spontaneous: It's really no different from the blood that collects on your uterus before a period, your body knows what to do and you should trust it. Expect cramps to follow but the uterus is doing it's job. It also may just absorb the clot. Give it time. But if you have fevers or severe pain, see a doctor.