need some advice... the first time I was pregnant my husband and I were ttc and we had sex October 3rd and 4th of 2013 well come October 17th I was cramping but wasn't late I was suppose.to start the next day so I thought nothing of it so I took a test and sure enough I was pregnant so that was 13 days after we conceived I found out which was super quick after 1 try, but here it is 3 1/2 years later and we weren't trying and I wasn't in my fertile window I had already had my period and was out of my fertile window by 3 days and we has sex November 6th well I was suppose to start the 17th and I'm a week late today I've had light cramping for a few days and I wiped a min ago and had rusty brown light spotting I'm not sure if it's implantation bleeding which would be a first bc my first pregnancy I didn't spot or have it and I've also taken 2 tests one on the 17th and one yesterday and they are both negative so I'm just trying to find out if it could be implantation bleeding and if so if it's possible how many days do I need to wait to test again if it ends up not being my period?