Well she got her shot on august 23 , she thinks but so she has been having her periods & So her next schedule is on October 31 but she had sex today which is October 28 and but before that she has been feeling like or thinking that she pregnant because she's been stopping some little spots on her underwear & but she said she wouldn't really think that she pregnant because its said that those 3 months wont that she has the shot most likely to not prevent it to be , she just a little worried that it . i care about her so can you guys please help me out here? She only 16 years old .