Advise please

Hi guys, my husband and I have been trying now for about 9 months. I am usually like clockwork yet I am currently 6 days late. I may be jumping the gun but have never experienced this before. I have been feeling nauseous for the last few days and today have had severe cramps and slight spotting (brown) I took a test two days ago that was negative. Has anyone experienced this before? Any advise welcome. Thanks.x