Well, some women have fertile cervical mucus for several days, while others only have it for a day or two. In general, your last day of fertile mucus is the day you ovulate, but sperm can live in fertile cervical mucus for days, so they recommend starting to have intercourse
As for stretchy cervical mucus (or EWCM = EggWhite Cervical Mucus), most women will get wet cervical mucus first, followed by stretchy. But not everyone. For some women, wet cervical mucus is their most fertile.