hello i have a question about pregnancy. i had a menstrual in March 2016, none in April but had sexual intercourse on April 30th and May 1st i started brown disharge very light that lasted the 2 days, took pregnancy test from April 27th- May 19th all NEGATIVE, then May 25th my menstrual came so I though good im not expecting But as of JUne 23rd, 2016 i tested POSITIVE , how can i calculate how far along i am or do i need an ultrasound to be exact