Threatened miscarriage

Yesterday I went to the hospital due to vaginal bleeding and period like cramps . Drs gave me a vaginal ultrasound and said everything was fine . Went home & cramps got worse and bleeding got worse with small clotting . Went back to hospital and was told nothing other then in the paperwork I received that said threatened misscarrage. Has anyone else bled like this and carried their baby without a miscarriage ? This is my first child I'm freaking out tremendously .