Twins????? can somebody help me please lol?

welll....i have found out im pregnant and have done a test which says im 4 weeks! which would make sense as i had my last period in May. Now this is my second child...my first is a year and a half old. The things that are puzzeling me is that im already feeling flutters...not gas (i can tell the difference) and im also showing very much!!! it looks like im 3-4 months alrady when im only 4 weeks!!! and i have a craving for tomatoes!!!! which i have NEVER liked ever not even in my first preganancy can any one give me some advice?? i know i shouldn't be feeling any of this yet as im still really early! do you think im further along even though my period and test confirm different?? or maybe twins?? im totally confused!! lol