@Rose07 There are several different questions really - Whether there is a life for us beyond this world? If there is can anyone who has died come back to us in some form? What do each of us believe?
If there is an afterlife, it will be there whatever we believe, just as if there isn't one then belief won't make it so.
I'm a Christian, and it's fundamental to that faith that we are passing through this world on our way to somewhere else. I'd say for myself that this is something I know rather than believe - and have done since I was a small child. It's not a thinking but a feeling thing for me - feeling in the sense of deep intuitive awareness.
It's quite a separate issue whether that means anyone can come back and visit us from beyond death. That I don't know in the same way. There seem to be many accounts of people over the long ages who have had contact with the dead - and there are You Tube videos of people who have had near death experiences which included meeting people very dear to them in those experiences. In the main these things appear to be as intangible and elusive as encounters with UFOs.
It seems to me quite possible that your mother is coming to you and giving you comfort. There are other very possible explanations too. Our unconscious minds are rich and deep and have a will of their own - we can see this in our dreams, which weave stories that we didn't choose consciously, but which may sometimes bring things that matter to us that we aren't aware of and need to be. This can happen in our waking lives too in the form of feelings and awarenesses that appear to come from outside us - if they catch us on the borders of sleep, you may even get an impression of someone or something actually there, or hear a voice calling you.
An experience may well involve both a real encounter blended with one that comes from our unconscious - and in truth this is no different with our living loved ones.
But how wonderful to receive those hugs - maybe they matter far more than any rationalisation or explanation for them?