@SnowWhite1985 - That happened to me in June/July - my cycle suddenly went long, but I was getting negative pregnancy tests. The uncertainty was horrible.
I realised afterwards that I'd probably ovulated about 10 days later than expected - which in turn had delayed my period. Despite an LH surge at the expected time, I'd had a particularly stressful week, so my body 'tried again' at a later date.
So I'm sure there's a strong link between stress and my cycle. It may be similar for you. The impact of thinking about all this stuff can be surprisingly powerful. I don't think it affects everyone the same way, but I'm a major overthinker at the best of times!
Like you, I prefer to gather as much information as possible. When it's something negative (like a bad result or even something odd, like a late period), I go through a sort-of 'shock' phase for a few days, where my stress really peaks and makes me feel terrible - and it becomes a vicious circle.
I don't think there's any way to avoid it completely, unfortunately... so in between, I'm going to try to be sensible and rational; and hope that it outweighs the bad times.
We're going to get all these tests done and then see what the experts advise. I've panicked in case fertility clinics won't treat someone with bad results (which hadn't previously occurred to me!)... but apparently some places specialise in 'natural' or 'mild' IVF, which is specifically aimed at those with a low ovarian reserve and focuses on quality over quantity. But I need to do a LOT more research, for peace of mind.