Could my period be break through bleeding?!

My boyfriend and I have been TTC for just a month now and usually my periods are normal and are heavy the first three days and then light the last three days and oddly enough my period came yesterday which I didn't think much about besides that it came 2 days early... What got me was that it's really light. I could have probably gotten away with wearing just a panty liner all day today.. Has this ever happened to anyone before and they were actually pregnant or maybe just because it's all wishful thinking.?..