I would go back. I had ivf and so had support from the clinic. It was nhs and not the kind of support I have had subsequently in private clinics, but easier access to services than I had once discharged to maternity services. I was actually bleeding before test day, which had happened the previous cycle and was my period, but they said to test anyway on the test day.
It said positive. So they had me come in for blood tests. The next day, I was tested. I was still bleeding. I answered the questions and they were v sympathetic and said that because of the quantity of blood, it was unlikely that I had a viable pregnancy, but that they would ring and tell me the numbers.
I do not remember the numbers now, but low, so it was reiterated that it was unlikely to be a viable pregnancy, but not impossible, so I should go back in 2 days to see what had happened the levels.
That day, I knew I needed the level to have doubled to indicate viability. It had not. It was up a tiny amount, but not nearly enough. I was booked in for a scan a week later and we discussed that if there was no fetal pole and my bloods were not reflecting what was necessary, I could potentially have a d and c and go back to ivf asap.
One week later, I had a scan. There was a wee heartbeat. So early it was not really a beat, but an off beat flutter. There nonetheless. Beside it was a wee collapsing sac.
Sometimes numbers are not the whole story. My 7 year old was that wee flutter.