Talk to Gynecologist on Spotting After Periods

I am newly married a month ago....I got periods every month on time mostly 2 days before..the problem is when my periods get over and I take ghusl on 14 day after periods I see red spot on my penty it's happening since 2020 so it's not related to marriage at all anyways previously it happen only for 2 3 days just spotting no need of pad etc I use to wipe off from tissue...but now I see red spot till 7 8 days same case no need of any pad I used to wipe it off from tissue I consulted this issue in Pakistan with Dr Halima Hashmi she sits in liaquat national hospital .she did my pelvic ultrasound and it was all fine she said it's IMB issue take famila 28 till 21 days..you have to start taking it from 5th day of your periods and stop it after finishing white tablets don't take brown tablets.. so I started this medicin from yesterday since yesterday was my 5 day. My question is would it cause my period cycle irregular I mean I have regular periods cycle uptil now so will it disturb my cyc