Need other opinions

I’ve posted so many times today, I’m sorry 🙈. I’m just really starting to freak out.

Here are 4 pictures, the first one was with FMU and I think it’s a faint positive. I took another a few hours later to compare and it’s definitely negative. Following those two are the inverted pictures.

Here’s some back ground, I’m 6 months postpartum and haven’t had a period since baby was born in September. I have a Mirena IUD, so I wasn’t expecting to have a faint positive. But I’ve had some pregnancy symptoms the last few days so I thought I’d test and this is what I got.

What do you think? Is the first test positive? Is it just a fluke? I already called my midwife and left a message, she’s going to call me back later today. I just need some reassurance. This is so stressful!