mess up

On day 16 of a 28 day cycle I had sex with no condom for a bit but then used condom about fufteen minutes into sex. On day 26 of my cycle the condom broke and he came in me. It was super late in my cycle so I wanted almost 48 hours and decided to take plan B. Today is day 30 of my cycle and still no period. Today I had spotting and don't really feel good. I fully expected to get my period but I am also stressed from finals. My boyfriend is also freaking out which isn't making it much better (don't mock him he has anxiety problems). How worried should I be.