Well, implantation bleeding is a very important pregnancy sign, because it’s the earliest indicator of successful conception. However, you never know if you can actually count on it. You might not have it at all or, on the contrary, the discharge you take for implantation spotting turns out to be caused by the hormonal imbalance or an inflammatory process.
Anyway, if you’ve got the desired sign about 1 week before period, chances of pregnancy are very high. So, when can you finally confirm your assumptions?