Thank you for your query at DoctorSpring.com
I understand your concern.
With a proper condom use and it not tearing, you have already negated any chances of STDs by almost 95 %.
Only in some rare cases, if the partner has an open lesion ( for example herpes sore ), due to contact between the genital areas, even with condom, infection can be transmitted. But then this is not true in your case, because if she indeed have open lesions, you would have definitely noticed.
Do not worry about the outer area of condom touching your penis head, infections can't be transmitted like that, because invariably everyone while removing their condom will have some partner fluids on their penis. It is not enough to cause any infection. Hence only unprotected sexual intercourse can spread HIV and other similar STI's.
I will one again reassure you, you have nothing to worry about.
Feel free to discuss further,
Patient replied :
Hi Doctor Sebastian, I very much apperciate your response. Could you please elaborate what is the 5% of chance that condom would not prevent STD? So would you recommend that I take no action in this case? or get myself tested at an anonymous sex clinic (HIV, and other kinds of STDs)? Many thanks again for your expert advice.
Yes the 5 % chance I was referring too is mostly either because of wrong way of applying the condom or the open lesion situation which i mentioned about.
You do not have to worry at all and there is no need for any testing.