just started the pill - foggy head?

Ally
hi!! i've just started the pill and i was wondering if it's normal to feel like foggy headed? i highly doubt it's a side affect but i've been so worried about becoming really moody etc!! is there any way to prevent any side effects such as weight gain? (well like apart from exercising etc ahaha 😂) 
any advice / answers would be very greatly appreciated ☺️