My wife's fertile window was last week we had sex about 12 times last week and this week she started bleeding very lightly, it's pinkish and bright red, and she's cramping. Her period isn't due for another week. Could this be implantation bleeding? We're really wanting another baby and aren't sure if she should test or wait until next month to bc she's had the lift spotting for two days counting today and the day it started and today it stopped.