They won't do anything wrong, they just won't work as effectively. They definitely won't turn toxic, that's rubbish.

I would use them if you are worried, it can't hurt. I was on crinone until 6 weeks then a few days after I stopped I started spotting so they restarted me on them, might have been coincidence but I felt better taking it for a few more weeks. I think at our age we need all the help we can get ;-)