Yeah- I wouldn't be as specific as it being before, during or after as all of our bodies are different- some ladies don't retain water at all and don't need to account for it.
You will gradually see a pattern- the important thing is not to get despondant if the scales don't seem 'fair' around that time
Another thing is- don't use it as an excuse! lol. I know someone who doesn't lose or gains for 3 weeks every month and says it is because it is the week before/week of/week after her period!!!! She didn't lose any weight at all last year and still convinces herself it is due to bloating (and not McDonalds)