If you're 16 weeks pregnant, or think you are, you REALLY need to see a doctor and get the appropriate medical care for the baby.
Babies need to be monitored, you need exams and blood work and to take prenatals.
Being a teenager and pregnant already adds risks to not only you but to the baby. Get to a doctor.
I agree, it's impossible to have a period while pregnant. If you think you're pregnant, WHY have you not seen a doctor yet? Pregnancy is nothing to toss on the back burner and just let go. You need to see a doctor ASAP.
You can't have a normal period while pregnant. It's not possible, as a period is the shedding of your uterine lining, which is necessary for pregnancy. Some women do experience bleeding while pregnant and mistake it for a period, but it is not a true period. If you were to be 16 weeks pregnant, it would show up on a home pregnancy test by now, so I highly doubt you are pregnant. Though if you really think you are, make a doctor's appointment to get a blood test done to check your hcg levels. While you are there(if you are not pregnant), you may want to talk about birth control options as well to prevent pregnancy. Hope it all goes well.
Some women experience regular periods while pregnant, you should go for a blood test, and is your belly growing????