United Kingdom, Feb. 1 -- Megan Fox "just wants to focus" on her pregnancy.

The 38-year-old actress is currently pregnant with her fourth baby, and her first with her former fiance Machine Gun Kelly - and Megan is determined to focus on her unborn baby, rather than drama in her love life.

A source told PEOPLE: "They tried to make things work for many years. It was exhausting for Megan.

"She's done with him now. She just wants to focus on the baby and her boys now."

The Hollywood star - who already has Noah, 12, Bodhi, ten, and Journey, eight, with ex-husband Brian Austin Green - "doesn't have much contact" with the 'Wild Boy' hitmaker, even though they're expecting a child together.

However, Megan is feeling upbeat ahead of welcoming...