Pregnant or not :s help!!

So I usually have regular cycles (32-35 days) and a 7 day period with moderate to severe cramping.  We are TTC and on the 21st of February we had sex (I was ovulating). I started bleeding at 4am on March 5th and it seemed like it was a normal period. A bit lighter then normal with barely any cramping at all however. Then on March 6th it seemed to stop completely. The next day 7th in the evening I had a bit of bleeding  not enought to even wear a pad or tampond just light pink or brown when I wiped after using the washroom and that continued until the evening of the 8th and nothing since. Since then I have had some mild cramping in my lower abdomen, bigger breasts that are tender, and soooo tired. On the 17th I did a pregnancy test but had a BFN :( my symptoms haven't gone away and I don't know what to think.  What do you ladies think? Should I test again or just do the tww. What else could be causing me to feel like this? TIA ladies.