weight gain question...

Hey ladies! I was wondering if y'all could help me understand how much weight I've gained (I know sounds silly) so my prepregnancy weight was 143lbs in the first months I lost 20lbs once I was able to keep food down again I gained it back and got up to 143lbs again... now I weigh 147lbs (32w) and my dr is telling me I need to gain more weight because I've only gained 4lbs but I thought I had gained 24lbs since I gained the 20 back... do the 20lbs not count because it was weight I lost from the pregnancy?