Pleaseeee Help😩

Me & My Boyfriend Had Been Together Almost 3 Years! Our Relationship Anniversary Is Feb. 18 Which Is Coming Soon. But Lately We've Been Arguing Non-Stop About Everything & I'm Starting To Feel Like Our Relationship Is Going Down The Drain & Since Our Whole pregnancy Scare He's Been Acting Really Different & I'm Starting To Think He's Cheating. But We Never Get A Chance To Talk Because We Always Arguing. What Should I Do