Grieving comes in many different ways.
My husband passed away around the same time as your mother, the funeral is tomorrow, and so far I have only had a few tears here and there.
I think it is a mix of things - the fact that we have been in coping mode for so long, not just with funeral arrangements now, but building up invisible, protective walls around us over the years to numb the pain just so that we could get through the days and be strong for our loved ones.
It's self-preservation, but that wall has chinks in it and gradually it will come down, but it doesn't necessarily come as an opening of the flood gates - for many, like us, it will be piecemeal.
I also agree with comments that, as carers, there have been lots of moments down the years where we have shed tears as the disease took its toll on our loved ones. My flood gate moment was the day they told me that my husband would need to go into a nursing home - nothing before or after that moment has had that same level of impact on me.
I have no doubt that you too have had moments down the years where something has happened to bring about that same kind of reaction.
You know you loved your mum beyond words just as I know I loved my husband beyond measure. The fact that we are not crying as much as we think we should takes nothing of that love away. The coping and self-preservation mode are still firmly in place, but we will come through the process of grief in our own good time.
Don't be hard on yourself and don't question yourself - it is as it should be, there is no right or wrong in this situation