HIV tESTING. Testing after the exposure.

Hi Doctor, I am a male from India working in Dubai 31 years of age and my wife is India. My question are as follows. 1)Since Last August 2015 I have been regularly visiting massage parlor once in a month to be precised 11 times till 30 April 2016 every time I visited a massage parlor I got myself mastarbated from the massauses (hand job) and are there any chances of Hiv infection in the above mentioned case. 2)Since I have last visited the massage parlor 30 the April 2016 I have conducted following test. #1 day after last visit - hiv 1 and Hiv 2 P 24 antigen test. #11 days after last vist-elisa test #20 days after last visit -tridot test #25 days after last vist-rapid test at Ictc center in India #55 days after last visit- hiv 1 and hiv 2 p24 antigen test. All tests are negative do I need further testing.i did not have any sexual encounter since 30 April 2016. 3)What is the window period for testing after the exposure.