shorter periods and fertility

hi all! i am just wondering if anyone happens to know, do shorter periods affect fertility or ovulation as a whole? my periods used to last about 5/6 days and were really painful for the first couple of days. since i started exercising and eating better they remained the same but the past couple of months they’ve only lasted 3/4 days maximum and have also been a bit less painful? is this a bad thing? i have had a hectic few months with moving house and starting a new job, i am wondering if this is the cause for them suddenly changing? i haven’t been on any form of contraceptive since april 2021. we are currently on the waiting list for 3 cycles of nhs funded ivf - consultant is treating us as having unexplained subfertility as all our tests have came back normal? i have had so far a day 21 blood test done sometime in 2022, hsg, amh blood test and internal ultrasound which showed i was ovulating normally as the dr could see my ovary almost releasing an egg, ovulation was confirmed with opk - this was around september time last year (2022). my hsg was done january 2023 and showed clear tubes and normal womb shape/size no abnormalities spotted. bf has had 2 sperm analysis done in 2022 which both showed normal. only thing that’s worried me is i apparently have a low amh for my age (i’m 25 - a few people have told me amh levels can change and to ask for it to be retested - consultant told us it doesn’t affect chances of pregnant/fertility but can influence the amount of medications needed for the ivf process to give us the best chance of it working) just wondering if the sudden change in period length/pain was something to worry about or if it’s a good thing? should i mention it at our next appointment? or mention to my gp? this is all a huge thing for me and i am looking for some experiences and advice on this please x