My dog might be in heat

Question
hi there! i was looking over different adds about dogs and their heat cycles and im still not sure about my dog.  She is a very small weenie dog and i just got her a few weeks ago.  the lady i got her from lives across the street from my boyfriend and she first said that the dog was born in February but then she said she was born in January.  If she was born in January then she would be about 6 months old right now.  I have always takin her over to my boyfriends house and he has a weenie dog too.  He has never really tried to "hump" her before until now.  Last night i was watching through the window at them and he was trying to mount her and she was trying to fight him off, eventually he succeeded (he is much bigger than her).  I was yelling at my boyfriend to go and stop them and as i was yelling i was watching.  At the risk of being vulgar i want to tell you everything to get the right answer, his "red Rocket" was not even out when he was humping her but he had done the proper procedure that i saw on the Nat. Geo Channel by  licking and everything first.  I brought her inside right after i made him get off of her.  This morning i put her out there to go potty and then rode to get breakfast with my boyfriend.  I came back to pick her up to bring her home to my house and i saw him on her again.  She has not really shown any signs of heat, like no bleeding, and her vulva are not swollen.  So you think she is in heat, and if so, could she already be pregnant just from the little incident last night and this morning? (she has not been over there all week except for that and he has never done this before).  Please let me know what you think! Thank you very much!!!
Savannah

Answer
Hi Savannah,

Firstly, you must separate the two dogs, and not allow them to be together. That is totally in your control, and it's also your responsibility.

Second, NOW is the time to get your dog Spayed.
There are significant health benefits that your female dog will gain from being "fixed", but it must be done before she has her first heat cycle.
Spaying before the first heat cycle eliminates the possibility of uterine or ovarian cancer and greatly reduces the incidence of breast cancer. It eliminates the chance of developing a serious and potentially fatal infection of the uterus experienced by many mature unsprayed animals (Pyometra). Spay surgery also eliminates the heat cycle and associated mood swings and undesirable behaviors, messy spotting and the attraction of all available males to your yard.
Spaying will help your dog a live longer, healthier life.

Please do not delay in having your dog spayed. There are many reduced cost spay/neuter clinics. Contact your local animal shelter or Humane Association to see where there is one in your area, or your vet can do the surgery.

Your boyfriend's dog should be neutered too. Neutering decreases the chances of developing prostatic disease and hernias, and eliminates the chances of developing testicular cancer. It also reduces problems with territorial and sexual aggression, inappropriate urination and other undesirable male behaviors.

Lastly, your dog is called a Daschund, not a "weenie dog".

Best of luck,
Patti