On march 20th I had sex I took a morning after pill later on that day I received my period on April 1st or April4th which I was happy about now it is may 14th and I have yet to see a period. I took a pregnancy test on may 8th it came out positive but yet faint... On may 9th I went to get an ultrasound but it showed nothing, I want to know did I conceive in march or April?

Not enough information at this time, When they do another ultrasound latter they may have a better idea of the age of the fetus. While it is most likely April, there is a small chance it could be March, the morning after pill is not 100 percent and a side effect of the pill is some bleeding.
The morning after pill also makes you miss the next period or two at times.

Did you confirm the home pregnancy test at the doctor with a blood test to be sure you were pregnant ?

The thing is I didn't have some bleeding it was like a normal period for me no spotting and no implantation

I took the morning after pill march 20 and my period came on April 4th but when I get the age of the fetus I will let you know

When you took the pregnancy test, when did you read the results? Was it within the first several minutes or later on?