月经周期时间是怎么算的

来自周颖医生的专业解答，快打开看看是否又获得了新的知识点～

https://m.baidu.com/bd_page_type=1/baiduid=84A6E5D6E016785179491BFD571B4516/t=mip/tc?ct=54&lid=30861160093221&module=mip&cst=91&clk_extra=%7B%22pageid%22%3A%2230861160093221%22%2C%22searchID%22%3A%2230861160093221%22%2C%22nPageID%22%3A%2230861160093221%22%2C%22mip_logid%22%3A%2230861160093221%22%2C%22masterpage_type%22%3A%22self%22%2C%22originalUrl%22%3A%22https%3A%5C%2F%5C%2Fm.jkzl.com%5C%2Fdoctor%5C%2Fmip%5C%2Fmip_question.html%3FquestionId%3D5103690%22%2C%22srcid%22%3A%22landingpage%22%2C%22name%22%3A%22A%5Cu533a%5Cu6b63%5Cu6587%5Cu6298%5Cu53e0%22%2C%22id%22%3A%22expand_content%22%7D&tcreq4log=1

https://m.baidu.com/bd_page_type=1/baiduid=84A6E5D6E016785179491BFD571B4516/t=mip/tc?ct=54&lid=30861160093221&module=mip&cst=112&clk_extra=%7B%22pageid%22%3A%2230861160093221%22%2C%22searchID%22%3A%2230861160093221%22%2C%22nPageID%22%3A%2230861160093221%22%2C%22mip_logid%22%3A%2230861160093221%22%2C%22masterpage_type%22%3A%22self%22%2C%22originalUrl%22%3A%22https%3A%5C%2F%5C%2Fm.jkzl.com%5C%2Fdoctor%5C%2Fmip%5C%2Fmip_question.html%3FquestionId%3D5103690%22%2C%22srcid%22%3A%22landingpage%22%2C%22name%22%3A%22A%5Cu533a%5Cu6b63%5Cu6587%5Cu4e0b%5Cu65b9%5Cu4e2d%5Cu95f4%5Cu5c55%5Cu5f00%5Cu6309%5Cu94ae%22%2C%22id%22%3A%22new_expand_content%22%7D&tcreq4log=1

健康之路

病情分析：您好，根据你的描述，在临床上，月经周期是指：本次月经的第1天直到下次月经来潮的第1天中间间隔的时间即为一个完整的月经周期。正常的月经周期一般是21-35天，提前或者是推迟一周都是正常的。

周颖

副主任医师

提示：本内容仅作参考，不能代替面诊，如有不适请尽快线下就医

问题描述：想问一下月经周期是怎么算的啊？想知道正常的月经周期是多久呢？