Can your period be a month late and you be pregnant?

My friend and I tell each other everythingg. And her period was about a month late, She was on the pill but not taking it everyday which was causing breakthrough bleeding, although we didn't know that the bleeding meant the pills weren't working. So, technically she wasn't on the pill. And the condom ripped. She was having all the symptoms of being pregnant except for the implantation bleeding. And It doesn't take the implantation a month... right? So, could she still be pregnant or was it a false alert?