PLEASE HELLLPPP- Period a day late?

I started my placebo pills this morning, and my bf and I are sexually active. I take my pills perfectly, I’m super anal about it and we always use a condom when we have sex. A day last week, we were at the beach and in the water fooling around. He slipped only his tip in (no condom) and then took it out after the fact. Should I worry at all about not starting my period yet? After all it is day one of placebos. My friends say I should be perfectly fine but I’m a little anxious and wanted other opinions.

Thank you for your help girls! Btw, yes I know how sex works.