HELP???

Ok weird question but how many balls does your uterus have?I have a Dr apt coming up but I've had 3 negative test & all the symptoms for over 1 month plus SO has symptoms too.I am most certain I am pregnant & if so this will be my 3rd pregnancy.My 1st miscarriage & my 2nd will be 1 1/2 come Christmas.I have been feeling what feels like a hard ball like a knot but tonight I felt two hard knots.Could this be my uterus or twins?