Pregnant or is she crazy??

Guy I’ve been seen for the past few weeks have been great. Untilll tonight i decided to stay the night & his ex gf showed up at 3am.. long story short she told him she was pregnant. She is CRAZY. At least from what he tells me. He made her pee on a stick and it was negative. Do you think it was a manipulation tactic or you think she could be pregnant but to early to test positive? We’ve only been seeing each other about 2 weeks.