I don't know what to think

My husband and I have been ttc since August of this year it will be our 2nd child. My period is ALWAYS 7 days! This last month it was 6 days late and only 3 days. I took a test 5 days ago (before I went to bed) and it was negative. With my daughter I had my period the first month and got one positive and one negative test and didn't it didn't show up til I was 2 months pregnant... it took over a year to get pregnant last time I hope it doesn't take that long this time :(