Why do my guppies keep dieing?

ok so i have a 10 gallon tank and i started out with 4 guppies . all of the 4 died but 1 by 1 one died randomly(probbaly sick) one died becauseshe got stuck in a bush(stupid) one got stuck to the filter(...) one just died like a week after pregnacy now i got 4 more but like i said one by 1 so far one just died today and that was a male so i have 1 male and 2 females im tired of spending 20 bux for fish that are gonna die! i know that your gonna respond saying did u cycle your tank and YES I DID!... like a month ago i got water from my existing tank then put 8 gallons in there and 2 chlorinated water and waited 48 hours i tested my water and everything was good. anyways about 3 weeks later they started to die now i have three gupies(1 pregnat) i dont want them to die i just tested my water and everything is good and under control. i have about 10 fry and none of them are dieing they have like 7 big plants in there tank and i took the big bushy 1 out and now 7 plastic ones wtf???????