Should I count the first day of spotting or first day of proper bleeding as the start of my last period?

Question

I'm unsure whether to consider the 18th (first day of spotting) or the 20th (first day of proper bleeding) of last month as the beginning of my last period. If I choose the 18th, it will make me appear further along than I actually am. Which date should I count as the start?

Answer 1

Count the first day of proper bleeding just as you would count that day to track your period.