My daughter took a test in early Feb she was a few days late and it came back neg. then a few days later she had a "slight period" that only lasted a couple days. Then missed her period all together in March. Took the test and it came back Pos. So at that time she thought she was only 6 weeks pregnant but come to find out she was pregnant when she took the test back in feb. She did the exact same thing with my now 8 yr old grandson. They had her due date by her last period even the ultrasound said october and he was born Sept 1st and the head nurse said he was over baked.