Think I'm having a miscarriage

Started heavily spotting and cramping yesterday evening. It's very irregular, i have had 2 period like bleeding since the first spotting. I went to the ER yesterday and my baby is still in there but soo small that it is hard to detect a heartbeat. Now i'm just waiting till my second check up on thursday to see if the baby has grown or not... Crucial times. Any one who has experience or tips