Do you think it's a real thing? I sure as heck do. For example today; I was doing my Saturday morning duties and noticed the newspaper I used to use to wrap up my used pads (sorry if tmi). So I thought (and this was right after showing my daughter's father a comparison picture of last week and this weeks belly bump) "hmm...I haven't had my period in a while, I should probably get a pregnancy test. Oh yea..." If that's not pregnancy brain, I don't know what is. Or simply paying for $1.25 with a ten dollar bill. Then leaving. Walking halfway down the street. Then realizing you paid ten dollars for that ice cream and running back. Yup, did that too. A lot.
Achieve your health goals from period to parenting.