Implantation question????

Do you have to get implantation bleeding in order to be pregnant? I have a five year old and I really don't remember bleeding at all not even a spotting type bleeding before I found out I was pregannt. Then again I had taken a test one day and it was negative. I took the second test a couple days later as a joke just so I hadn't wasted my money on a test and WA LA, I was pregnant with my son!!!!!! Seriously though can I be pregnant without the spotting or bleeding first???