Yes it is supposed to be very good for trying to conceive. I will copy paste what I read about it.
I just started taking it myself a few days ago. Just one tiny 81mg of baby asprin.
Why take baby aspirin?
Well, I believe it does suppress natural killer cells in the uterus, so it is used for those with immune problems. It has other effects on the immune system that I don't fully understand - I will try to find out more. But, it also improves blood flow to the ovaries, improving follicle development, and improves blood flow to the uterus, improving the quality of the uterine lining. This increases the odds that implantation will be successful. Also, during pregnancy, it will help to prevent mc or fetal demise in those prone to blood clots. Having blood clots form in the placenta and/or umbilical cord in the cause of many of these pg losses.
There's a great article in People magazine (the one with Di on the cover) about a women who had failed many IVF, presumably due to a weak uterine lining. Her sister agreed to be a surrogate but they also decided to give both women a few embryos. They both got pregnant. They said they don't know why this worked when all other attempts had failed but they think it was due to her starting to take baby aspirin 2 weeks before the transfer.
A good friend of mine just got pregnant after 10+ years of infertility (PCOS). It was a complete surprise. They were even using condoms!! But, they only thing different she did was she started taking daily aspirin for an unrelated reason several weeks before conception!
My clinic (Biotexcom, Ukraine) has also given their blessing for me to take it.