Pregnant after tubes clamped?

So I had my tubes clamped 6 weeks postpartum, in march of this year. My baby is now 8 months, my period returned when she was 8 weeks old & has been regular. But now I have missed 2 periods in a row & am feeling very bloated and nauseous. I know there's a slight chance it could happen, but I was wanting to hear of actual people who became pregnant after having their tubes clamped (or tied or however). Thank you!