Low HCG and cramping

J-

My OB and high risk doctor are telling me I won’t have a viable pregnancy. That I’m either miscarrying or have an eptopic pregnancy because I’m 3.4 weeks and my hcg is only 169. I’m also having mild cramping and some brown discharge on and off. I’m when I look up HCG levels it says that number is still in normal range so I’m confused why they are saying it’s too late without an ultrasound to confirm? I’m devastated.