this happened to me as well and I freaked out and asked my doctor about it. She said that it is perfectly normal, something to do with hormones peaking at around 8 weeks but I reckon it is probably to do with the placenta as well. All I remember is "perfectly normal" LOL.

Word of warning though....I felt awesome for 2 days (apart from being nervous about the loss of symptoms, namely nausea) and then it all came back LOL. About 10 weeks though the nausea started to ease of and was mainyl first thing in the morning and in the afternoon. This gradually got less and less until around 14/15 weeks. From about 13 weeks my boobs stopped being as sensitive and I stopped needing to have afternoon naps. Still a little tired now though and I'm still waiting for the fantastic second trimester feeling to join in.

Glad you're feeling better and hope it lasts for you. Not long till your 12 week scan hey?