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I am very much concerned with your problem and certainly will guide you how to get rid of these.
In my view
You wait for 12 day from the missed period date and there is no period even then than do a pregnancy
test of urine done.
There is no other way to detect pregnancy at this early time.
I suggest you to
Wait and see with no tension as you can’t do anything more than to wait.
Dr Agarwal VL