Do i have a shot? Or am i thinking to much into it.

Stephanie • I have 2 amazing kids a girl whos 6 and a boy whos 5. They are my world. I had a terrible car accident in november when i was 14 weeks and lost my 3rd child with the man ive been with for 2 years now.
So heres a pic of my month. I made sure me and my boyfriend had sex on the most fertile day. The break is due to work schedules. Anyway i just got a cold yesterday and mind you, its been 90 degrees. My period should of started on sunday per glow. Never did, yesterday i had what i thought was the start of it. Used a tampon and when i went to change it, it was brown but only a little and nothing after. I took a preg test this morning and it says neg. Im sooo hoping i am pregnant but i cant help but think im not. Any opinions or past experiences would be helpful.