The horizontal space between margin and *align* environment

Question

How can I remove the space between margin and align environment

\documentclass[a4paper,14pt]{article}
\author{}
\usepackage[fleqn]{amsmath}
\usepackage[a4paper,margin=1in,left=2cm,right=1cm,top=1.5cm, bottom=1.5cm]{geometry}

\renewcommand{\baselinestretch}{1.5}
\AtBeginDocument{%
\setlength{\abovedisplayskip}{0pt}%
\setlength{\belowdisplayskip}{0pt}%
\setlength{\abovedisplayshortskip}{0pt}%
\setlength{\belowdisplayshortskip}{0pt}%
}
\date{}
\title{}

\begin{document}
\maketitle
normal text
\begin{align*}
\frac{1}{2}+\frac{2}{3}=\\
\frac{3}{6}+\frac{4}{6}=
\frac{7}{6}\\
\end{align*}
\end{document}