Question about syphilis

i got tested a couple weeks ago and came back positive for syphilis and treated after with two penecilene shots ive never had any type of std of any sort so i had a lot of questions but got no answers or education about it and my follow up literally isnt until the end of next month which has left me distressed snd concerned since they said it was likely an early infection but i never had any symptoms what so ever no blister or anything that would alert me so my question is ..is it possible that ive might gotten it inside my anus since i saw no visble signs ?!i contacted my last sexual partner but he came back negative so i feel so lost and confused i was on the phone with a sex health person and she said i probably have had it for over a year since he didnt get it ?! but like i said i never noticed any signs ..

May be your partner has performed RPR test which not detect syphilis in early stage and give false negative , on this stage he need to do VRDL test .
if u have no symptoms not mean that u dont have syphilis , chancres may come and ho without you notice it because in may cases it is not itchy or painful