My husband has poor morph and potentially low volume as well. I will tell you that we got pregnant on pretty much the 2nd month of trying with my son so we never knew there was even an issue.
I also have a good friend that was told that there was no way they could conceive naturally, and lo and behold, she got pregnant on her own and now has a son as well. It DEFINITELY can happen and I also think that sperm quality can vary over the years. I don't think that it is something that stays constant or even declines the way the female body does!
I would take a test tomorrow! You definitely could be pregnant!!!! Good luck!!!