Confused 🤷‍♀️

Tricia • Mommy to 2 handsome boys 💙 and a beautiful little girl 🩷

So I had my Mirena IUD placed back on June 26th and have not had any spotting / cramping or any of the usual side effects that I’ve been told or read that would happen. About a week ago I was feeling super nauseous, lightheaded, horrible headache, backaches, and off and on cramping but they were super light. Decided to take a few pregnancy tests to rule out possible pregnancy but they have come up with very very very faint lines never have gotten any darker. I have not yet had any form of a period, just this morning I had very very very light pink spotting not enough to really show up on toilet paper my OB says this is normal 🤷‍♀️ I’m just confused is it normal to stop having periods immediately after placement of the IUD? Everyone I’ve talked to says they’ve always had spotting or bleeding for at least 3+ months.