Okay here is what I remember...

Sesshomaru was with Kagome...he got her pregnant and left because he didn't know. While she was still pregnant, she was spotted in the mall by Sesshomaru's mother who identified her by a crescent moon on her forehead. I think it symbolized the mate of Lord or something. Anyways, she jumped to conclusions and believed Sess's father cheated, but after they realized she was carrying Sesshomaru's baby.

That's all I remember...

Anyone know which fic this is?

It may be Winds of Change by KogasAngel. If it's not, it's a good read. Sesshoumaru accidentally mates Kagome and she gets pregnant; he leaves her because Yura tricks him into thinking Kagome used her powers to seduce him; in chapter 7, Sess's family sees Kagome at a restaurant, she has Sess's markings, Sess's mom thinks dad cheated on her again, etc.

Thanks for the fast reply! I'll check it out XD