My boyfriend an I have been trying to have a baby the last few months.

I missed my period suppose to be on the 1st of July. Never happened. Lots of negative test.

On July 16 through the 18th I thought I had my period. I had no cramps. It's was a very short and very brown/ dark red. Not enough to fill a tampon. Any ideas?

I have 2 other kids and never had this at all.

Thank you.