TTC while BF

Ok so I am feeling a bit down at the moment and just wanted to write it down.
I am breastfeeding my 11mth old and my periods still have not returned yet. (I have had 2 since birth but nothing regular & nothing for a few months).
My partner and I decided to ttc #3 a few months ago. Last month we BD'd and then 1.5 days later I noticed a lot of EWCM. Not thinking much of it because my daughter is still feeding a LOT...I forgot about it. Then about a week later I started feeling extremely tired, so tired I could barely function...this was not normal. And is not normal before AF. Then my back started aching a lot in the mornings...this had only happened to me when I was pregnant with #2. Then the nausea started...getting worse as the days went on. But every single test I did was a BFN! Since I have not had a regular period for 3yrs I have no idea when my period should be due but it has almost been a month since the BD and no sign of AF. I am still feeling very pregnant. Tired, bloated, slightly nauseous, achy back. I have had a very high libido this last week which is abnormal for me except in the early months of pregnancy. Oh and I am also extremely moody! Which is also weird as I am usually pretty level headed. I am starting to think that AF is definitely around the corner but not sure when it should be making an appearance. Tonight I was cramping a fair bit...was very painful. Thought for sure it was AF coming as my monthlys are usually very painful. So confused at the moment. Am wondering if anyone has taken a month after ovulation to get a BFP?