Your cm is determined by the varying levels of hormones. In natural cycle, before ovulation, oestrogen is higher which causes your cm to be more watery/lotiony and gets thinner, clearer and stretchier as ovulation approaches.....following ovulation, when progesterone is higher, your cm becomes thicker and creamier.
With IVF, whilst your stimming, when oestrogen levels rise, many women notice their cm becomes more abundant (cos you're usually producing alot more follicles than in a natural cycle) and also more watery/lotiony and even like ewcm........and then following EC/ET and during 2ww, we're given progesterone support which will then cause our cm to be thicker and creamier, just like in a natural cycle.....and it's likely to be more of it because of all the drugs.
Unfortunately cm can't be used as any indication one way or another I'm afraid....I always get lots of cm but sadly it's not always been a happy ending for me.....and been the same on the times I have conceived too.
Fingers crossed it really is a good sign for you....but I'd try not to read too much into it.