GREAT JOB!! You can safely take your brew for another 20 days. Wormwood used at 100mg per day for 20 days will not cause any problems - but you need to swallow the powder whole OR in a capsule - it is the second most bitter herb known to man and is not good in a tea. Black-Walnut is the most effective against Tapeworms and can be taken in powder form also - 200mg per day for the 20 days.
You might be passing adult tapwworms - most species are only 1/2 inch long and are easily mistaken for pieces of a "mother" tapeworm. I wish you continued success!