Talk to Gynecologist on Menustral Problem (gynaecosid,Sinovac Vaccine Or Nursing)

I am 29, lactaing mom of 20 months old daughter who was born by c section. I recently started to (pure red blood not brown) spot for a day after every 7 to 10 days of my periods and this continued for 3 months. Three months back I had taken (unfortunately) 2 gynaecosid tablets once only just get good periods and after that cycle I started to spot after 7 day (one or 2 spot of blood) and this keeps appearing after every cycle (2 cycles until now). My Dr did my scan a doubted infection (and said she can't see any cyst but little water in or with follicles) and we started antibiotics course. It's been 12 days late until now , and yet there is still no signs of my periods. Sometimes I feel pain like period cramps but no stains nothing at all. I (wasn not) am not on any Birth control medication. Tested negative pregnancy test. I have never been this much late from my periods. Sometimes I doubt that It's due to nursing but I am nursing my baby from month 1 and after 7 months with no pe