Clingy Toddler? Sensing Pregnancy??

So I have a 2.5 year old daughter who is usually super independent but now has just in the last week suddenly become super clingy!!! She has also started begging to breastfeed again when she has been completely weaned for 7 months! My period is due in 6 days and maybe this sounds crazy but I'm wondering if maybe she can sense that I am pregnant!? Has anyone else had a similar experience and then it turned out you were in fact pregnant?? We have been trying for baby #2 for 13 months now.