bloods need taken on cd 21 but it's a Saturday?

Natasha • I`m 25 years old, I had excision surgery for stage 4 endometriosis in October 2016. Endo already growing back due to trying for baby. Husband has testicular failure. Looking for positivity 💞
Hi ladies I need help, I need my bloods taken on cd 21 but it's a Saturday what do I do? TIA