BBT - DPO dips am I out ?

Sw
Hi Ladies
Really confused why I have dips on 2dpo & 4dpo. I definitely did ovulate as I use the Clearblue digital dual hormone OpK and got a positive. My CM was ewcm until Sunday when it went creamy yellow. I just don't understand these temp dips ! I have not seen a temp surge above 98 like I did last cycle after ovulation. Any ideas if I am out?