Worried (TMI)

After having a miscarriage last year. We got our first positive since then on Christmas. I am about 6 weeks along. I worked all day today (literally, 5 am to 7 pm). I noticed after I got home that when I went pee I had started spotting (light pink) so my nerves have already kicked in. Next time I went to the bathroom (about 15 minutes later) the spotting has turned brown. I'm freaking out. I can't handle another miscarriage.

Can someone please put my mind at ease is this normal? I'm trying to calm myself down but I can't.