Each time I've been pregnant I've had symptoms from three-ish weeks. Because they have been IVF transfers, I've been acutely aware of the sensation of the embryo implanting - feels much like a little alien trying to munch its way out from the inside of the uterus. Part of the reason I didn't believe I was pregnant this time was because I hadn't felt implantation... It is entirely possible to have symptoms very early, but it is unusual.

BW