Using dilators during your period

I am on my 4th out of 5 dilator and my progress is going fantastic (moving up sixes every 2 weeks as recommended by my physical therapist) However, I just got my period and tried using the dilator and it felt super painful and very tight. I use my dilator everyday with barley any pain now so this was rather out of the ordinary. I’m just wondering if others feel more pain when using the dilators while on your period as well?