Positive hpt but negative blood??

Okay, this is so weird. So yesterday morning, I got a faint positive FRER & on a clearblue. I had a dr appt later that day at 1:40. She drew my beta hcg because I just finished clomid. I figured it’d all come back fine. But she just called today and said it’s negative, my hcg is 4. Blood is obviously more reliable than urine tests, especially clear blue, so I was like ok whatever I’ll try again next month. But I just had an urge to test tonight, and I’m testing positive across several brands and the FRER is much darker. And it’s from a different box/batch/etc. How would they get darker if I’m not pregnant !? what in the world!!! First pic is what I took before the dr. Below it is my FRER tonight (both within time frame)