Spotting during the first trimester..

Maricela
Please help! According to the Dr. I am about 7 weeks (basing it on my first day of my last period) but my BBT chart tells me I'm 4 to 5 weeks..I've been spotting for 2 1/2 days now it's not enough for a panty liner but it's there and it's goes from dark red to brown to red. Is this normal, Nurse is telling me it's normal but how much and Color is normal? no cramps, no pain only spotting.. any comforting advice is greatly appreciated.. Looking for a group of girls to start a group as well, I'm 35 about to be 36, first baby.. Thanks