ovulation or implantation, opinions?

I'm 21, my lmp was 5/7/11, my cycle is a advrage of 27 days. On the 18th and 19th I had brown blood in my discharge only when I wipe and a little pink in it on the 19th. I've been tired and having really bad cramps, to were I'm expecting my period to come early anyday now, and nausea. My husband and I were intamate on the 1st, 11th, and 16th of this month. He is currently in training for his up coming deployment so doctor is out of the question for 3+ more weeks. With my last pregnancy I didn't shown any symptoms til around week 5 and never had implantation bleed (that pregancy ended in a miscarriage at 9week) so I was hoping to get some opinions/ thoughts since I have a little while to go before I can take a hpt. Thank you.