Nexplanon implant question

So, I have had my implant for over a year and I noticed something about my periods.

When my husband finishes inside me, I have a small period. So I was having a period every other week and it was driving me crazy!

So I asked him to not do that anymore and now, guess what? Periods totally back on a normal cycle!

Why do you think this is? Does Nexplanon do some sort of flush-out when you have the chance of pregnancy? Was I having miscarriages? I don’t know what’s going on, but I am so glad to have only one period a month now.