I think I completely forgot to take the pill one day on the last week, what now?

As the title says, I think I forgot to take a pill last sunday. The reason why I'm not sure is because I got hospitalised that day and the medicine they gave me made me forget that day entirely. I can't rely on my pill packet because my mother was managing it and she is unaware too.

I stop taking it today (wednesday) and the day I'm unsure I took a pill was last sunday, 3 days ago, on my last week of the 21 days before the placebo week.

Am I in trouble? Should I expect something, any side effects? I take Diane 35 if it's needed to specify.