Spotting - worried !!!

Valie • my heart 6/16/16
Hey ladies, I know most of you are further ahead than I am. I'm 5 weeks and 2 days along and I've had some spotting today. Bright red at first and then continued to be like water consistency but red and then brown. I've had back aches yesterday and cramping down there today.....I'm also walking with a limp from all the progesterone I'm taking.. has anyone been thru this? Im just so worried. My first us was scheduled for Friday but now I'm going in tomorrow instead. Is it normal to feel like your going to get ur period? Gosh I'm so worried.