1. If your partner has an oral hsv1 infection, then yes, it is possible, but not probable, to acquire an hsv1 genital infection. The odds are strongly against you getting herpes this way. Based on what I know about long term discordant couples where one partner is hsv2 positive and the other is not and who are having sex as much as three times per week, your odds of acquiring an hsv1 infection from someone who has oral hsv1, but is not having an active outbreak, is less than one in several thousands.
Do you know if you are hsv1 positive? If you are, then your odds are zero for intents and purpose. Even if you are not hsv1 positive, the odds are very low.
2. A primary outbreak will start at the point of greatest friction during sex - the shaft of the penis in men - and can emanate out from there. In someone that is negative for both hsv1 and hsv2, a primary outbreak tends to be quite severe. You likely will not miss it or mistake it for anything else.
3. If those were herpes blisters on your penis, they would have become fluid filled by now and would probably have popped and developed painful lesions by now.
4. It could be trauma to the skin to to vigorous rubbing during oral sex, or possibly abrasions due to your partner's teeth scraping your penile skin during oral sex.