ROSE: There's five of us now. Mum, dad, Mickey... and the baby.
THE DOCTOR (taken-aback): You're not...?
ROSE: No. (Laughs). It's mum.
The Doctor laughs with some relief and looks over at Jackie.
Doomsday transcript
Can I infer from this that The Doctor thought that Rose was pregnant with his child because Rose was just sucked into parallel universe and he didn't know that Rose was there for 3 months? Actually, I automatically inferred that when The Doctor said "You're not...?"
Other than that, I have seen The Doctor kissing Rose, Amy, Martha, Elizabeth I, River Song in the new Doctor Who (2005). While it is clear that
Elizabeth I and River Song were his wife
they won't be counted as his companions (correct me if I am wrong).
Also, it seemed like The Doctor had sexual affair with Marilyn Monroe.
RORY: Your phone was ringing. Someone called Marilyn. Actually sounds like THE Marilyn.
AMY: Doctor?
DOCTOR: Tell her I'll phone her back. And that was never a real chapel.
A Christmas Carol transcript
But, I don't know if she was The Doctor's companion/associate. Maybe, someone who has watched the original Doctor Who can enlighten.
I got a new name when River Song accused The Doctor in The Husbands of River Song:
The Doctor: So, King Hydroflax?
River: Oh, how many times? I married the diamond.
The Doctor: So you say.
River: Elizabeth I.
The Doctor: Ramone.
River: Marilyn Monroe.
The Doctor: Stephen Fry.
River: Cleopatra!
The Husbands of River Song transcript
Was Cleopatra his companion/associate? I think, I have heard that she was indeed his companion/associate. Possibly, I have seen her in a dinosaur episode.
Also, I haven't watched the original Doctor Who of 60s.
How many companions/associates has The Doctor brought to the bed at least once?