Pregnant after mc

I had a mc in june and just found out monday that i'm pregnant. I had blood work done that day. She said that my levels were high enough that they would just see me at 8 weeks. I also have a healthy almost 3 year old. This evening i started spotting it was pink and pretty light and it stopped. I'm 4 weeks and 1 day. Should i be worried. With my previous mc i never bled. I didn't know that i had miscarried till 12 weeks at my ultrasound and had to have a dnc.