Period/Vag Questions

So this might be TMI ladies and I apologize in advance but I need to check with other women to see what might be going on. So I have an IUD but I still get a regular, yet light, period each month. After this months period my boyfriend says that my vagina feels more lose and it does feel different when we have sex. So some back story is that I absolutely am not sleeping with anyone else and so it’s not from another man and I also have had a lot of white discharge As well. Is it a thing that your walls can expand right after your period or could something else be happening? Has this come up with any of you ladies? I’m just trying to figure out why it would change all the suddenly.