Test confusion

Backstory: my boyfriend and I are possibly pregnant. He has cycled steroids for years and was told two years ago by a urologist his chances for being fertile were slim to none.

The first day of my last period was March 4th. I have a very regular 28 day cycle. Today is May 17. I've been having a small amount of fatigue, cramping like I'm about to start, bloating, queasiness, mood swings, painful feet and back ect. All of which can be either stress or a period, but the period never comes. This is 43 days late according to the app I've used for the last few years. It hasn't been wrong before. Here's where my confusion comes in. I've taken 9 pregnancy tests. Each has been negative.. except the last two I took (one in the morning and one in the afternoon...paranoia), which were negative at first. I tossed them in the top of my trashcan and noticed a few hours later later that they were both positive. Could this be evap lines or positives? I've had two babies before but the tests were always immediate positives.

I have set an appointment for Tuesday at a free pregnancy Care clinic near me.. I'm going to be asking for a blood test and/or ultrasound.