Should I ask for blood tests?

Hello, I dont know much lingo so please bare with... I am currently on CD35 and im a regular 28day woman within a two hour time slot to be precise! Me and my fiancé have been trying for a baby for 4 months now and this month I'm a week late.. ive tried several hpt with one clear blue plus having the most faintest of lines but only in certain light so ive discarded it as a negative.

This morning I've experienced a dark brown discharge but only when I wiped (sorry tmi) and it only lasted 2hours?? Is this normal and is this my period about to show or is this old blood from the implantation period? Im too distressed to try another test incase it comes back negative!

I've got history of Ectopic pregnancies and still borns in both sides of the family and I am scared that this could happen to me.

Can I ask the doctor for a blood test or should I sit tight for the next few days?? And has anyone been in the same boat??

Many thanks xx