That's such a shame, so sorry for you. We borrowed a tup one year and only one ewe conceived, the tup was too small and too young in my opinion but the owner - an old shepherd - insisted he would do his work nevertheless. I'd suspect the ram is at fault in the case of your ewes, for what comfort that gives
At least you have six lambs to look forward to, lets hope they are mostly female
We had our first two lambs yesterday morning, nice big twins 9lb 11oz and 8lb 5oz. The tup had 24 days with the ewes and then went off to the mart because it's time for a change. All my ewes have good udder development so I know he did his job thoroughly. I have a very natural approach to all this stuff, no sponging, scanning, or starve and flush. The lambs stay with the ewes all summer on good pasture, never need to buy creep feed either they grow like mushrooms without that stuff. Then the ewes get about 8 weeks to fatten up before the tup goes in.
I think that only having a few acres means the tup is never so far away that the ewes cannot small him so they are ready when he says they are. If he starts wooing them and pacing the fence I know they are ready. If it's too early I move him and his companion wether to where he can't see them. He tends to have covered them all in a very short time so lambing isn't a long affair.