Possible chemical? Very confused :(

Hello all!

This past Sunday and Monday, I had two positive pregnancy tests. I made an appointment for this Friday, the 12th.

This morning, I took two more tests, to see if the lines would be darker....both tests, including the digital were negative. 🥺

What is going on?? I have no spotting or bleeding. I've had some bloating/gas and cramps, but nothing severe. My boobs are tender and I've had a bit of nausea.

I am currently 13dpo with none of my normal signs of AF. This is my first time ttc.

Thank you for your insight!!