I drastically cut my dairy intake, no milk, no yoghurt, only occasionally a bit of cheese or dessert with dairy in it, for an entirely different reason: I thought this might help with migraine, but instead found it drastically reduced my period pain. I do not use ibuprofen or any other painkillers for period pain anymore at all. I've also found my period is lighter and shorter. This change has now gone on for over a year, and it's entirely clear to me that my period pain is in direct relation to the amount of dairy I consume.
Have you been having and cramps along with your periods. It could be cramps and they do range in severity. Cramps can be debilitating I know that how it works with the women in my family. I dont think it will have any effect on you having a baby later. It sounds like they are cramps. Maybe you should talk to your doctor about them.