No. They are conceived on the same date.
try ultrasound.
When you do the ultrasound they see it.
At the first ultrasound
An Ultrasound can be done to find out.
The only sure way of knowing you are pregnant with twins is by ultrasound. An ultrasound at 8 weeks would show if you were carrying a multiple pregnancy.
Ultrasound once you're pregnant.
Three weeks pregnant is a week before you miss a period so it is impossible to know it is twins. If you are three weeks after conception, (5 weeks pregnant)it is still early to see a heartbeat.
You are having twins
Twins who are of the opposite sex or do not look alike are fraternal twins ~ not identical. This means that at the time of their conception ~ two eggs were fertilised. In the case od identical twins, one egg is fertilised and split in half.
You will find two heartbeats at the ultrasound.
You will probably find out when the doctor runs the ultrasound and two bodies pop up.
Having sex is a good way to start to conceive. However, conception of twins depends on the splitting of the egg, or upon several eggs being produced at once. Twins often run in families, leading to the strong possibility that the conception of twins is a genetic feature more than happenstance.