I am on cycle #3 of TTC and my period is getting wacky. I really, REALLY wanted to be pregnant by now (many reasons) and am not.

I have been spotting for 4 days, light brown after a very short 3 day period, one day medium. negative HPT.

(Background: 30 y/o, 28 day cycle, normal BMI of 21, 10-12 day luteal cycle, no meds, had benign follicular cysts 2 years ago but BC cleared them up I think.
After turning 30 my periods have gotten WAY shorter and lighter. I was training intense for a triathlon but have reduced exercise a lot. )

I know of course I could call my doctor for this but I know she'd brush me off and give me the textbook answer (spotting after a period is normal and could be the result of your uterus expelling old blood) blah blah blah.

Could it be stress? Does anxiety/ obsessing over pregnancy make you spot like this?
Am I ruining my chances of getting pregnant by putting so much pressure on myself to get PG by August that I'm messing up my cycle?! ahhhhhh!