I can offer no assistance when it comes to Baby Brain (it’s hopeless...) but from the neck down, I can help!
Not only is strength training whilst pregnant safe but it is also advised by many experts, unless there are extenuating circumstances of course. The stronger and healthier you are, the more likely it is that your labour will be safe and speedy and similarly, your recovery too.
Hooooowever, as I’ve mentioned before, working out when pregnant is different - it is not a solo act. You’ve got to consider the little one inside you: If you overheat – it overheats. If you’re struggling to breathe – it’s struggling to breath. (This is as much a lecture to myself as to you guys by the way.)
Having said this, there’s no reason to limit yourself to a few butt-clenches whilst reading The Economist. That can be supplemental if you like. With a lighter weight than you're use to: If you really concentrate on your reps +put your mind on the muscle being worked +execute the movement at a slower pace, I promise you’ll feel the heat and reap the rewards – it’s called: TUT! Time Under Tension: The slower your rep the longer and harder your muscle fibres have to work.
Not to liken you nor I to a forklift truck, but once the baby is here we will be doing A LOT of: Lifting, lowering and carrying so here’s a circuit focusing on your Back, Shoulders, Arms, Core and Legs.