5 weeks today and dark spotting.

I am 5 weeks today, this morning when I went to the bathroom I wiped to find dark reddish brown on the tp. I am freaking out bc  I had spotting with my first pregnancy but I was way farther a long when it happened. I am constantly going to the bathroom now and have minor cramping, but idk if that's just in my head bc I am thinking the worst. I have my first ob apt tomorrow but don't know if I should go be checked out today or wait until tomorrow. Help?!? Anyone else have this?