Miscarriage opinion

I got pregnant with an iud in place. I found out last Saturday and hcg levels were 403 and 2 days later 677. On Tuesday IUD was removed and levels were 449 and today (3 days later) it was 476. Idk what my body is doing. I am spotting occasionally only when I wipe, no pad needed, and it is red. Doctor said numbers should be going down. Anybody had experience with this before??