Any advice?

Ta
I'm not sure if this is the place to post this and I'm truly sorry to all the women that have had to go through a miscarriage! I'm very confused at the moment... I found out I was expecting around November 3rd. Around November 12th I started spotting. It was pinkish at first and has been brown/red on and off. I went to the E.R. On the 13th and drew my blood and my levels were 544 and thy saw what was the beginning of a gestation al sac and the tech said it was a very early pregnancy. I also am RH- and had to get a rogam shot. Five days later my ob had me come in and took blood and my levels rose to 1100 something. I know that's very low and she also put me on progesterone pills 100mg a day. Sorry for the long post but I was wanting advice on if any of you ladies had this problem and had a successful pregnancy later on? I know my chances are low so I'm prepared for the worst. I'm also worried that taking progesterone will delay me having a natural miscarriage?