Please help!!!! No hpt at the moment!

I haven't really started trying yet since my fiance is currently working in another part of the country until March, so I only get to see him one weekend a month, but I downloaded this app in preparation.

Anyway.. he just so happened to come home for only one day last month and according to glow it was one of the days I o'd. Well I haven't thought anything about it whatsoever, especially when I started spotting on the fifth (af was due anywhere between the first and the sixth). The tampon I had put in that morning came out with just the tip a little pink/brown after my whole work day...I thought it was just slow starting, but then the next day my tampon came out completely un touched. Then this morning I put a pad on and after all day there is a faint dusting of super light pink. I've never in my life had a period so light. I had implantation bleeding with our first daughter, but it happened about a week before af was due. I guess my question is could it be implantation bleeding so late? The 19th is when he was home. Thanks! Sorry it's so long!