I Went To The Hospital Last Night Due To Heavy

I went to the hospital last night due to heavy bleeding and severe cramps. They did a urine pregnancy test (negative) then did a beta qualitive test which came back borderline positive, then did a beta quantitative test that showed over a 2. They told me I was 2 1/2-3 weeks pregnant and diagnosed a possible threatened abortion. I have an appt on Tuesday to check my hcg levels again, how much should they increase in the next 5 days if I am pregnant?