Is my dalmation molly pregnant?

Ive had a female D.M.,(Dolly!), for almost a year now.A few months ago i added a black molly to my tank,she became pregnant shortly after and she gave birth a while later.UNfortunately all babies were eaten after making it thru the first 4weeks :( Anyways,she is now the only molly in a tank with guppies,a swordtail and a fighter fish and she appears to be pregnant again!! Is this possible?or is she sick?