Help would be greatly appreciated!

I am on the contraceptive pill and have weekly breaks for my period. I stopped taking my pill last Saturday (as usual) on Sunday, I had protected sex with my boyfriend (condom). He did not finish whilst we were having sex. However, I am now worried as it is nearing Friday and I have still not started my period, I usually would have by Tuesday. Any help or advice? Am I overthinking? This has never happened before and I am really worried about pregnancy!