How to get a period back to normal 28 days


​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​My boyfriend and i want our kids close together so we are trying for baby number 2 we had baby number one almost a year ago but I haven’t been having a normal 28 day cycle like i did before the pregnancy I am not breastfeeding I’ve tried to use ovulation test because I don’t get any EWCM so i don’t know when I ovulate and my periods is not normal anymore