Possible implantation bleeding,BBT dip, negative pregnancy test

Patient: Hi there. We are trying for a baby. my periods have ALWAYS been VERY heavy and last for four to five days, heavy the entire time. i was excited to see my latest period was very light, only lasted three days (was a different colour to my usual heavy flow) and it began only 21 days from the first day of my last period. I do have fairly short cycles anyway though(average 25 days). the day this light, short latest period began was nine days past ovulation (using ovulation predictor kits) and in doing some reading i thought, excitedly, that this may be a heavier implantation bleeding. BUT just took a pregnancy test (a very sensitive one) at 12 days past ovulation and the result was, unfortunately ­čÖü negative ­čÖü – I would just except this and move on and eagerly await my next ovulation phase but im a tiny bit hopeful with my period being so out of the ordinary that maybe…..maybe it was a heavier implantation bleeding and i am pregnant. another factor is my BBT which i have been charting for 3 months. so after my last ovulation my temp stayed elevated from my coverline (consistently for 6 days at 36.60ish degree Celsius, cover line has been around 36.40 degrees Celsius), was very excited. then on the day my light, short period arrived BBT dropped 36.37 degrees Celsius, i had read about the ‘implantation dip’ and though this is it!! then temp rose to 36.47, looking good i thought but the next day (so the last day of my light, short period) it dropped again to 36.27 – today it was up again a little to 36.40. and also about 7 days past ovulation i felt EXTREMELY tired, falling alseep on the couch at 7pm for two days in a row.OK so thats everything. as i say i would normally just except the negative pregnancy test and move on but with the dip on the ‘right’ day and the very abnormal period im just wondering, is there a chance i might still be pregnant, or maybe if the egg got fertilized but then i miscarried early?? HELP!! am i totally over analysing this?? – thanks, from baby crazy!