Pregnant then Not Prwgnant digital

Please help. I am grasping at straws needing some insight...

I got a positive first response on Monday. It got a slight bit darker on Tuesday and Wednesday. On Wednesday I also had a positive clear blue digital (pregnant 1-2). I went to my clinic that day and they would only do a urine sample which came out negative. Yesterday I didnt test. Today (Friday) I took a first response with FMU and the line was lighter than the first one I took. Then I took the second digital from the same box and it said Not Pregnant. I am 17 dpo and 3 days late for AF. No cramping or bleeding yet.

To say I am devastated is an understatement. We have been trying for 2 years. I know when this happens it usually means a chemical pregnancy/mmc is happening.

Has anyone had this happen but went on to have a healthy pregnancy?

Or am I most likely going to miscarry soon?

Thanks in advance.