How to deal with guilt when I’m not able to work as planned?

I really struggle with feeling guilty if I’m not feeling well (each month, I get really bad cramps that keep me down for 1-2 days) and due to that, I’m unable to get housework or business work done. It happened this weekend and now it means that if I don’t work this evening, I’ll start off the week behind (because I’ve already planned it out). Basically, if I choose “rest” I am worried about how this impacts the rest of my week. This feeling of guilt if I’m not able to spend time as planned is a repeat cycle.