I Don't Know What's Going On...

I'm on CD 56. My OD was on my Bday March 4th me and my SO had sex before, on, and after that day. Ever since 5dpo I was taking tests to see if I could get a line progression I got nothing but BFNs. I already missed my expected period so I thought "This is it, I'm pregnant." NOPE still getting Negatives with FMU. Now I'm approaching the second month of when I'm supposed to be expecting my period for April which the 18th and I took another test this morning also BFN. My symptoms are heavy soar boobs, bloating, and extreme mood swings. I don't know if my body is playing a joke on me or am I really pregnant and the tests just can't detect it? Can someone share some positive advice on what I should I do? Cause I'm losing hope as well as getting frustrated with myself...