What Causes Brownish And White Discharge And Delay Of Periods?

Hi Doctor, I am 27 yrs old, . Got married last year oct. Before marriage my periods will be 32-45 days cycle. After marriage it was regular
to 30 days. Last month my periods was April 17th. We are planning for Baby. This month
i din get my periods but after 8 days i got brownish spots with white discharge. Moreover
when i wipe it i could see the brownish and feeling tired, vomiting. I took HPT but
it shows negative. Brownish spots sometimes with fibre also ... I am worried? Please
help me.

Age: 27
Height :165 cm
weight : 65 kg