Side effects of switching birth control pill brands?

I've been on ortho tri cyclen for 6-7 years now. My body seems to be becoming used to the pill and not working as well now. I'm having frequent breakouts, heavier/more painful periods, crazy hormonal attitude explosions and some other things. My gyno suggested switching pills. She's putting me on Lessina and i start it in two days. Will there be any crazy side effects i need to worry about or look out for? weight gain? attitude changes? anything?