Even with the Synth Womb augment on "fertility" mode, submissive PC cannot get impregnated by dominant Sera. Tried it without the augmentation, too. I also saw in another thread that this was an issue for dominant PC/submissive Sera, too.
What sex scene are you using to try and get pregnant? The trained Sera "Ride" scene always ends with her not cumming in Steele. The only way for her to get Steele pregnant as a crew member and fully trained is with morning sex. Steele will need to not be sleeping with anyone. Sera will randomly come right before sleep to ask to sleep together. Have Steele spoon with her, in the morning there will be a sex scene. It is going to take some luck if your Steele has cocks and vaginas, as the morning sex scene will be random between her using Steele's dicks and vagina. Also do not have her sleep at the foot of the bed. That sexscene also ends with her not cumming in Steele.
Oh I see, you are playing with the dominate sera still at the shop. She is not virile unless you give her priapin. Even then, with your build there is only a 11% chance of pregnancy. It took a few tries but your steele did get pregnant from the priapin scene. Note I did it with the synthwomb set to normal. If you set it to max fertiity it should roughly double the chance.