implantation or ovulation cramps

I don't know if anyone out there can help me or not with this particular issue, but I guess I'll give it a shot anyways. :)

To get right down to it my periods are not regular and never have been. I've talked to my gyno about it and she said there was nothing wrong and some people are just irregular. My fiancee and I have been together for 4 years and do not use any form of protection. I was on birth control for about a year, but decided to stop and haven't taken it for about a year and a half so its well out of my system. The other night I felt period like cramps (with no spotting or blood) and I looked at my calendar and realized it was around the time I ovulate. I'm curious if it is really ovulation cramps or not because I've never had them before and I was told that if you get ovulation cramps it should be a common thing and they don't come and go. Which has me thinking it could be implantation cramps. I'm trying not to become obsessive because I don't want to start imagining symptoms of pregnancy or anything like that. I don't get headaches often and I've noticed in the last couple of weeks I'm more sensitive to them. I haven't had any nausea, but then again I literally haven't thrown up since I even had food poisoning once and didn't get the nausea symptom so I'm thinking that's a symptom I won't have in general.
I want to take a pregnancy test, but I know its way too soon.

Has anyone experienced anything like this before and ended up pregnant? I'm open to all information and advice.

Thanks.