Period or Not?? Flu or Not?

Mckenzie
So I fairly new and I have been TTC for 4 months now. I have have very regular periods every 28 days. Last months right on time I got why I believed was my period but it was a little different than normal. I normall just start and am fairly heavy for a few days and then tapers off. This month I spotted brown for 2 days , bled red for 2 and then Spotted brown 2 more days. 
I thought nothing of it and assumed I was out till I spent the entire next weekend throwing up but with no fever or body aches or anything which I always get with the flu. I have felt extremely tired like I constantly need a nap and can't decide if I haven't recovered from what I had or if it's pregnancy that I have overlooked thinking I got my period. I tested right before my period but it was negative so I haven't tested since. Has anyone had this type of situation or have period like bleeding and been pregnant. 
Thanks in advance