Hey, I took the first dose of the moderna vaccine earlier this month at 18 weeks. I didn’t feel more tired or sluggish than usual. Pregnancy got me feeling super lethargic already so the vaccine didn’t quite have that effect. I did have a mild headache the next day but didn’t need painkillers for it. Otherwise, I felt no side effects at all. I checked with my Gynae before booking a slot so you may wish to check with yours too.