Tumor in Ovary Can it cause hcg levels to drop

i have had bleeding for about a week with an ultrasound they found that i had a tumor in my ovary.they checked my hcg levels and said they had dropped.
Can a tumor or bleeding cause it to drop and is it possible for them to rise?

[AnnieBrooke]

Are you sure they said a tumor, or did they say a cyst?  Did a sac appear in the uterus in the ultrasound, or was ALL they saw the "tumor" (or cyst)?  In other words, did you get a positive diagnosis of pregnancy?  Or are you thinking that the tumor caused an hCG count?  In answer to your main question, once hCG counts drop, that is a bad sign for a pregnancy, and it is not likely they would rise again unless you had a vanished twin, which it does not sound like you have.  If "tumor" is really what they said and not cyst, what are they planning on doing about it?