when should my babies heart beat

so i posted before about my dad having weird dreams about me having a baby welp seems my dad was right lol

after i found out i realized the pains ive been feeling in my sides need to be taken more seriously so i went to the hospital they did ultrasounds and told me i am 5 or 6 weeks and they cant hear the heart beat and my blood pressure is a little high they want me to go back in two days and monitor my hormones they believe i may be having a miscarriage but i have no spotting and the pains on my side are fairly dull this is my first child ive fairly nervous and i left the hospital in tears did anyone else have this issue