Police found the SUV of a missing Fort Worth, Texas woman in a creek in Denton, Texas but there was no sign of Lisa Underwood or her seven-year-old son Jayden.

Underwood has been missing since Saturday when she failed to show up for her own baby shower. A pool of blood was later found in Ms. Underwood's home. An Amber Alert was issued for both mother and son and the search has been extended to include New Mexico, Oklahoma, Arkansas and Louisiana.

Authorities used dogs to find the SUV which was found partially submerged and abandoned in an undeveloped area of Denton, roughly 30 miles northeast of Fort Worth.

Local police suspect foul play was involved in the disappearance. 'What really causes us to be concerned for their safety is the evidence located inside the home,' Lieutenant Gene Jones said. 'We haven't made any conclusive determinations about what happened, but there is a great concern for her safety as well as her son.'

Underwood is a single mother and is pregnant with her second child. Jayden's father is being sought by local authorities in order to get more information about the situation.

Holy Pils, Underwood's partner in a local bagel store said she last spoke to her partner on Friday night. 'There's no one I know of that might want to do her harm,' Pils said.

Meanwhile, the search for Lisa Underwood and her young son continues.