My advice to you is to run.
If she is not pregnant yet she will damn well try hard to get that way.
This has happened to my ex husband twice, first girl he left said she was pregnant and she wasnt, the second told him she was getting the pill injection and she wasnt, she fell pregnant and they discussed termination which she agreed to, anyway their daughter is now 2 yrs old and he is living with her and she has absoulote control of him. (both weirdos)

Be careful very careful, the tests etc all look like fakes to me, but you can bet she will be trying really hard to get pregnant now.