Thanks for posting,
Since you have had your periods for Jan and feb there is no need for another pregnancy
tests. If you are pregnant it would not surely be as a result of the unprotected sex you had on 29th but probably a subsequent unprotected sex (and if you did not have any, there is no need to fear).
If you are feeling bloated then you are probably having an abdominal problem most likely indigestion
You need to consult a doctor who can examine you closely.
If you are still worried get an abdominal ultrasound
or see a gynobs.
Hope this helps