Whats going on with my pregnancy tests!?

Ok so i have been ttc a while now. I ovulated around the 9th december, then had spotting the 17th and 19th. I have had cramps (nothing like period cramps) the sides of my bbs have been very sore and have felt heavier. I have had odd headaches an nausea without being sick untill this morning. I took a test on the 19 and straight away there was a white line on the results window with a pink shadow around it. I took this as a BFN! I have just taken another test and it did the same thing! Im so confused and would really appreciate it if anyone who has experienced this or knows what it is could give me some answers please :) its driving me mad! Also the symptoms im having are ones i have never experienced when aunt flos on her way!