4+ months pregnant and didn't know...

Okay guys so I've just found out that I'm at least 4 months pregnant... I had still been getting periods up until this months and my friend asked if I was pregnant. I said absolutely Not, I've not had sex since Oct 22nd. I track everything. she said get a test and prove it then, so as a laugh I went and bought a test and was so sure that it was going to be negative that I went straight to the store bathroom and took it. boy was I shocked. 2 lines clear as day... no weight gain. no symptoms. regular periods up until now... no longer with they guy so this is going to be hard to explain to him... Any tips on how to break the news? Problem is, I've still been taking cerazette mini pill this whole time... will everything be Okay? any comments appreciated.