I don't have periods without birth control and haven't since I was 14.

Last year around early November I was pregnant and didnt know which resulted in a miscarriage and I was scared to have a period so, I didnt take my birth control until February this year. I haven't taken it since but, my boyfriend and I have been having unprotected sex since my last period and today I got light spotting that was pink (then turned brown) it only lasted for an hour or so and I'm worried it might be implantation bleeding. Does anyone have any idea what could be the cause and if there's a possibility I'm pregnant, what precautions should I take?