女，24岁，G<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20221202/13375836_0.gif">P<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20221202/13375836_0_1.gif">，平常月经规律，5～7天／33天，拟妊娠生育，末次月经为3月27日，其下次排卵期大约为