Early Pregnancy Symptoms

Okay, I've heard it around a lot of places that when someone is pregnant their SO may experience some symptoms that they should experience. ( morning sickness, heightened senses, lack of appetite). But has anyone ever heard of your mother getting the symptoms?

I mean we did BD last month on my fertile window, but AF came. ( yes I know that you can still your pregnant in certain cases and still get your period, but it's rare that it happens) We did it 3 times already this week, which I know that's not possible, but I know implantation still has to happen and other things have to happen in order for me to feel any symptoms.

It's just lately she's been saying that she feels like crap.

She's had major headaches and everything that she's had is what she when she was pregnant with me and my two brothers. She also has cramps that feel like pregnancy cramps and she knows what they feel like because she had three kids.

is this possible, or am I just trying to find a way to believe that I may be pregnant.