Regarding pregnancy. Please help!

I had my period on February 10 . But on March 10 I missed my period so I took pregnancy test on 16 March which came negative . Again I took test on 19 March which was negative again so my doctor prescribed me crina NCR for 5 days after which I started bleeding on 26 March . But the bleeding was light than always and was for 3 days I used one pad for 12 hrs . N usual spotting was there on 4 n 5th day which always occur when period ends. But in doubt I took one more pregnancy test on 2nd April which came negative . On 8 April I started seeing milky watery discharge from breast after squeezing .So my doctor gave me caberlin I took one medicine after which slight pain in breast is gone I will be taking second dose tomorrow but the liquid has not stopped yet . Is there still a chance I can be pregnant should I go for ultrasound . Today again I took pregnancy test which came negative .Isn't want to get pregnant . Please help