Jessica Sierra is Pregnant ... And Still in Jail!

Holy Jamie Lynn! TMZ has confirmed that "American Idol" trainwreck finalist Jessica Sierra done got herself knocked up -- and she's still in the slammer! Don't throw the baby out with the bathwater!

Sources tell TMZ that the father is a "rapper" and Jessica is ecstatic over the news. She's currently in the infirmary in the Falkenburg Road Jail in Florida on a "pregnancy diet." Jessica's spawn has a lifetime of fun to look forward to -- look, it's mommy in a sex tape! (Now available from Vivid Entertainment!)

Sierra is currently facing two misdemeanor charges of disorderly intoxication and obstructing or opposing an officer and two felony counts of possession of cocaine and battery.

She didn't win "American Idol," but she sho' iz famous!