Thanx for the query.
Ur fear is appropriate.
Well if you did not have periods it might be pregnancy
U will have to get evaluated by a gynaec.
She will do some blood test
and urine test.
Might be u require a scan too.
Secondly about ejaculation ....if the second person did not ejaculate there are no chances of pregnancy with him.because even if u had contact but there was no semene....means no sperms....so pregnancy chances are less with him.
Go ahead and visit a doctor.