so i just had my son 5 motnhs ago and for 3 months after i had him i was on the nuva ring.. last month i ran out and didn't get more.. but this month i had unprotected sex about 3 times before my period was due. i usually get it around the 20th but i got it on the 18th it was only spotting light pink and then it became dark brown discharge for 5 days. sometimes when i wiped i saw red blood though, a wee bit not much. i took a "5day before your missed period test" when i woke up and it was negative. whats going on???