my dog might be pregnant

i mated her on feb 4th and they where tied for about a half an hour now she sleeps alot not eating as much her nipples are swollen and pink she is always licking her private part she sleeps near me all the time even when i go to bed and when i try to touch her belly she kicks me away her valva has not gone down it is still swollen but as swollen as swollen like she was in heat under her belly below her ribs is starting to sag she also wants my attention all the time this is my first time maybe having puppies can someone please help me with this