trace of blood!?!?

So- got my positive test (finally)... told my hubby... two days later (today) tested again to be sure cause the first time the second line was pretty faint, definitely there, but faint.  Today it was pretty dark, that second line- lookin legit.  But then tonight when I went to the bathroom, a couple of times I thought I saw a faint hint or trace of blood.  AF is to start tomorrow... I'm terrified now that it's a chemical pregnancy and/or that imma loose it :( Idk what to do- is that normal to see a small hint of pink in the beginning or am I already losing the little one!?!? :(