Late Period, Negative CVS Test

Meghan
My periods are usually very regular, last about 4-5 days with medium-heavy bleeding. When I take the sugar pills during the week of my period, they seem to "jumpstart" my bleeding.
Last month, i did not bleed during my period. I took the sugar pills, still no bleeding. Very light brown discharge and tiiiiiny bit of red spotting.
This week, I am on my 4th day of my period for this month and still no bleeding. More light brown discharge this month and super tiny amount of red spotting I've seen. 
This is very unlike my body because I usually have medium-heavy blood flow on my period.
My other symptoms have been nausea (have not puked at all, just felt like puking), feeling weak/exhausted, body aches and pains, etc. 
I am on antibiotics currently for "chronic uti syndrome", has been 4 months now that I've been on antibiotics. This diagnosis isn't 100% confirmed but that is what they believe I may have.
I've been dealing w that condition since I was a toddler, so I know this doesn't have anything to do w missing my period.
Please let me know if you have any advice for me!!
I am going to take another test in the morning, but going to take a First Response one instead of CVS brand. Wish me luck!