Taurean - The second bleed that you mentioned I believe would have been breakthrough bleeding which I mentioned in my above post, this usually occurs when your period would normally be due. I agree that your first bleed/spotting would have been the implantion bleed.

Gosh our bodies are so complicated aren't they?!

Light spotting may occur when your fertilised egg attaches itself to the womb lining (known as implantation bleeding), but this is often so minimal that it goes unnoticed.

Another reason for early spotting is known as breakthrough bleeding, which may occur at the time when your period would have been due. This is caused by fluctuating hormone levels, and can continue on and off for the first 12 weeks, until the placenta takes over hormone production.