What to do if cd 3 for fsh test falls on a sunday?

We have recently seen an RE concerning IVF. I have orders to have bw on cd3 for fsh,estradiol and std screen(ours is a male factor, but tests are standard). Unfortunately cd3 is landing on a sunday. The RE's office is out of town and my ob's office doesn't do bw on the weekends. Should I go to a clinic lab on sat(cd2), try to see if the hospital does bw on sat/sundays(cd3) or wait until mon(cd4). I don't want to mess anything up or risk showing even slightly elevated levels since I am 37. Thank-you in advance for the information.