Help!

Amaya

So I took a plan b the day after my predicted ovulation day. My period is supposed to come in 9-10 days and I’ve been feeling like twinges on the left side of my stomach, as well as dull cramps. I’m also over 165 pounds and I heard plan b’s are less effective in women 165+? Is it possible that because of the time I took it and my weight that it was ineffective?