Talk to Gynecologist on Period Disturbance

Hi , was on hormonal pills for ,6,7 months almost a year ago , after that I used ecp for 2,3 time in a year . From past 4 months I have not taken any sort of ecp or or contraceptive . But I have noticed that my period timings has been disturbed by days .. My normal cycle used to be 26 ,28 days … It’s now 26,27 days , it once came at 25th day . Last month it was 27th day and this month it came 3,4days before , it my 23d day and a bit of spotting has started . There is no chance of pregnancy bcz I took strip test yesterday it was negative .

Can u tell me is this something to be worried about ..? Does contraceptive pills has long term side effects?